PyFile:TrailingCommaInList.py
  PyAssignmentStatement
    PyTargetExpression: x
      PsiElement(Py:IDENTIFIER)('x')
    PsiWhiteSpace(' ')
    PsiElement(Py:EQ)('=')
    PsiWhiteSpace(' ')
    PyListLiteralExpression
      PsiElement(Py:LBRACKET)('[')
      PyStringLiteralExpression: a
        PsiElement(Py:SINGLE_QUOTED_STRING)(''a'')
      PsiElement(Py:COMMA)(',')
      PyStringLiteralExpression: b
        PsiElement(Py:SINGLE_QUOTED_STRING)(''b'')
      PsiElement(Py:COMMA)(',')
      PsiElement(Py:RBRACKET)(']')