docs: docs update (#911)

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Fixes #<issue_number_goes_here> 🦕
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+
+<h1><a href="bigqueryreservation_v1beta1.html">BigQuery Reservation API</a> . <a href="bigqueryreservation_v1beta1.projects.html">projects</a> . <a href="bigqueryreservation_v1beta1.projects.locations.html">locations</a> . <a href="bigqueryreservation_v1beta1.projects.locations.reservations.html">reservations</a> . <a href="bigqueryreservation_v1beta1.projects.locations.reservations.assignments.html">assignments</a></h1>
+<h2>Instance Methods</h2>
+<p class="toc_element">
+  <code><a href="#create">create(parent, body=None, x__xgafv=None)</a></code></p>
+<p class="firstline">Returns `google.rpc.Code.PERMISSION_DENIED` if user does not have</p>
+<p class="toc_element">
+  <code><a href="#delete">delete(name, x__xgafv=None)</a></code></p>
+<p class="firstline">Deletes a assignment. No expansion will happen.</p>
+<p class="toc_element">
+  <code><a href="#list">list(parent, pageToken=None, pageSize=None, x__xgafv=None)</a></code></p>
+<p class="firstline">Lists assignments.</p>
+<p class="toc_element">
+  <code><a href="#list_next">list_next(previous_request, previous_response)</a></code></p>
+<p class="firstline">Retrieves the next page of results.</p>
+<p class="toc_element">
+  <code><a href="#move">move(name, body=None, x__xgafv=None)</a></code></p>
+<p class="firstline">Moves a assignment under a new reservation. Customers can do this by</p>
+<h3>Method Details</h3>
+<div class="method">
+    <code class="details" id="create">create(parent, body=None, x__xgafv=None)</code>
+  <pre>Returns `google.rpc.Code.PERMISSION_DENIED` if user does not have
+&#x27;bigquery.admin&#x27; permissions on the project using the reservation
+and the project that owns this reservation.
+Returns `google.rpc.Code.INVALID_ARGUMENT` when location of the assignment
+does not match location of the reservation.
+
+Args:
+  parent: string, Required. The parent resource name of the assignment
+E.g.: projects/myproject/locations/US/reservations/team1-prod (required)
+  body: object, The request body.
+    The object takes the form of:
+
+{ # A Assignment allows a project to submit jobs
+    # of a certain type using slots from the specified reservation.
+  &quot;jobType&quot;: &quot;A String&quot;, # Which type of jobs will use the reservation.
+  &quot;state&quot;: &quot;A String&quot;, # Output only. State of the assignment.
+  &quot;name&quot;: &quot;A String&quot;, # Output only. Name of the resource. E.g.:
+      # projects/myproject/locations/US/reservations/team1-prod/assignments/123.
+  &quot;assignee&quot;: &quot;A String&quot;, # The resource which will use the reservation. E.g.
+      # projects/myproject, folders/123, organizations/456.
+}
+
+  x__xgafv: string, V1 error format.
+    Allowed values
+      1 - v1 error format
+      2 - v2 error format
+
+Returns:
+  An object of the form:
+
+    { # A Assignment allows a project to submit jobs
+      # of a certain type using slots from the specified reservation.
+    &quot;jobType&quot;: &quot;A String&quot;, # Which type of jobs will use the reservation.
+    &quot;state&quot;: &quot;A String&quot;, # Output only. State of the assignment.
+    &quot;name&quot;: &quot;A String&quot;, # Output only. Name of the resource. E.g.:
+        # projects/myproject/locations/US/reservations/team1-prod/assignments/123.
+    &quot;assignee&quot;: &quot;A String&quot;, # The resource which will use the reservation. E.g.
+        # projects/myproject, folders/123, organizations/456.
+  }</pre>
+</div>
+
+<div class="method">
+    <code class="details" id="delete">delete(name, x__xgafv=None)</code>
+  <pre>Deletes a assignment. No expansion will happen.
+E.g:
+organizationA contains project1 and project2. Reservation res1 exists.
+CreateAssignment was invoked previously and following assignments were
+created explicitly:
+  &lt;organizationA, res1&gt;
+  &lt;project1, res1&gt;
+Then deletion of &lt;organizationA, res1&gt; won&#x27;t affect &lt;project1, res1&gt;. After
+deletion of &lt;organizationA, res1&gt;, queries from project1 will still use
+res1, while queries from project2 will use on-demand mode.
+
+Args:
+  name: string, Required. Name of the resource, e.g.:
+  projects/myproject/locations/US/reservations/team1-prod/assignments/123 (required)
+  x__xgafv: string, V1 error format.
+    Allowed values
+      1 - v1 error format
+      2 - v2 error format
+
+Returns:
+  An object of the form:
+
+    { # A generic empty message that you can re-use to avoid defining duplicated
+      # empty messages in your APIs. A typical example is to use it as the request
+      # or the response type of an API method. For instance:
+      #
+      #     service Foo {
+      #       rpc Bar(google.protobuf.Empty) returns (google.protobuf.Empty);
+      #     }
+      #
+      # The JSON representation for `Empty` is empty JSON object `{}`.
+  }</pre>
+</div>
+
+<div class="method">
+    <code class="details" id="list">list(parent, pageToken=None, pageSize=None, x__xgafv=None)</code>
+  <pre>Lists assignments.
+Only explicitly created assignments will be returned. E.g:
+organizationA contains project1 and project2. Reservation res1 exists.
+CreateAssignment was invoked previously and following assignments were
+created explicitly:
+  &lt;organizationA, res1&gt;
+  &lt;project1, res1&gt;
+Then this API will just return the above two assignments for reservation
+res1, and no expansion/merge will happen. Wildcard &quot;-&quot; can be used for
+reservations in the request. In that case all assignments belongs to the
+specified project and location will be listed. Note
+&quot;-&quot; cannot be used for projects nor locations.
+
+Args:
+  parent: string, Required. The parent resource name e.g.:
+projects/myproject/locations/US/reservations/team1-prod
+Or:
+projects/myproject/locations/US/reservations/- (required)
+  pageToken: string, The next_page_token value returned from a previous List request, if any.
+  pageSize: integer, The maximum number of items to return.
+  x__xgafv: string, V1 error format.
+    Allowed values
+      1 - v1 error format
+      2 - v2 error format
+
+Returns:
+  An object of the form:
+
+    { # The response for ReservationService.ListAssignments.
+    &quot;nextPageToken&quot;: &quot;A String&quot;, # Token to retrieve the next page of results, or empty if there are no
+        # more results in the list.
+    &quot;assignments&quot;: [ # List of assignments visible to the user.
+      { # A Assignment allows a project to submit jobs
+          # of a certain type using slots from the specified reservation.
+        &quot;jobType&quot;: &quot;A String&quot;, # Which type of jobs will use the reservation.
+        &quot;state&quot;: &quot;A String&quot;, # Output only. State of the assignment.
+        &quot;name&quot;: &quot;A String&quot;, # Output only. Name of the resource. E.g.:
+            # projects/myproject/locations/US/reservations/team1-prod/assignments/123.
+        &quot;assignee&quot;: &quot;A String&quot;, # The resource which will use the reservation. E.g.
+            # projects/myproject, folders/123, organizations/456.
+      },
+    ],
+  }</pre>
+</div>
+
+<div class="method">
+    <code class="details" id="list_next">list_next(previous_request, previous_response)</code>
+  <pre>Retrieves the next page of results.
+
+Args:
+  previous_request: The request for the previous page. (required)
+  previous_response: The response from the request for the previous page. (required)
+
+Returns:
+  A request object that you can call &#x27;execute()&#x27; on to request the next
+  page. Returns None if there are no more items in the collection.
+    </pre>
+</div>
+
+<div class="method">
+    <code class="details" id="move">move(name, body=None, x__xgafv=None)</code>
+  <pre>Moves a assignment under a new reservation. Customers can do this by
+deleting the existing assignment followed by creating another assignment
+under the new reservation, but this method provides a transactional way to
+do so, to make sure the assignee always has an associated reservation.
+Without the method customers might see some queries run on-demand which
+might be unexpected.
+
+Args:
+  name: string, Required. The resource name of the assignment,
+e.g.:
+  projects/myproject/locations/US/reservations/team1-prod/assignments/123 (required)
+  body: object, The request body.
+    The object takes the form of:
+
+{ # The request for
+      # ReservationService.MoveAssignment.
+      # Note: &quot;bigquery.reservationAssignments.create&quot; permission is required on the
+      # destination_id. Note: &quot;bigquery.reservationAssignments.create&quot; and
+      # &quot;bigquery.reservationAssignments.delete&quot; permission is required on the
+      # related assignee.
+    &quot;destinationId&quot;: &quot;A String&quot;, # The new reservation ID, e.g.:
+        #   projects/myotherproject/locations/US/reservations/team2-prod
+  }
+
+  x__xgafv: string, V1 error format.
+    Allowed values
+      1 - v1 error format
+      2 - v2 error format
+
+Returns:
+  An object of the form:
+
+    { # A Assignment allows a project to submit jobs
+      # of a certain type using slots from the specified reservation.
+    &quot;jobType&quot;: &quot;A String&quot;, # Which type of jobs will use the reservation.
+    &quot;state&quot;: &quot;A String&quot;, # Output only. State of the assignment.
+    &quot;name&quot;: &quot;A String&quot;, # Output only. Name of the resource. E.g.:
+        # projects/myproject/locations/US/reservations/team1-prod/assignments/123.
+    &quot;assignee&quot;: &quot;A String&quot;, # The resource which will use the reservation. E.g.
+        # projects/myproject, folders/123, organizations/456.
+  }</pre>
+</div>
+
+</body></html>
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