add EC WithNumbers interfaces and docs
diff --git a/docs/hazmat/primitives/interfaces.rst b/docs/hazmat/primitives/interfaces.rst
index ac47c1e..14be698 100644
--- a/docs/hazmat/primitives/interfaces.rst
+++ b/docs/hazmat/primitives/interfaces.rst
@@ -492,6 +492,23 @@
         The EllipticCurvePublicKey object for this private key.
 
 
+.. class:: EllipticCurvePrivateKeyWithNumbers
+
+    .. versionadded:: 0.6
+
+    Extends :class:`EllipticCurvePrivateKey`.
+
+    .. method:: private_numbers()
+
+        Create a
+        :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePrivateNumbers`
+        object.
+
+        :returns: An
+            :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePrivateNumbers`
+            instance.
+
+
 .. class:: EllipticCurvePublicKey
 
     .. versionadded:: 0.5
@@ -518,6 +535,23 @@
         The elliptic curve for this key.
 
 
+.. class:: EllipticCurvePublicKeyWithNumbers
+
+    .. versionadded:: 0.6
+
+    Extends :class:`EllipticCurvePublicKey`.
+
+    .. method:: private_numbers()
+
+        Create a
+        :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicNumbers`
+        object.
+
+        :returns: An
+            :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicNumbers`
+            instance.
+
+
 Hash algorithms
 ---------------