TypeRepresentation:a.pythonTypeRepresentation
  PyFunctionTypeRepresentation
    PyParameterTypeListRepresentation
      PsiElement(Py:LPAR)('(')
      PyReferenceExpression: int
        PsiElement(Py:IDENTIFIER)('int')
      PsiElement(Py:COMMA)(',')
      PsiErrorElement:Unexpected token
        <empty list>
      PsiElement(Py:RPAR)(')')
      PsiErrorElement:')' expected
        <empty list>
    PsiWhiteSpace(' ')
    PsiElement(Py:RARROW)('->')
    PsiWhiteSpace(' ')
    PyNoneLiteralExpression
      PsiElement(Py:NONE_KEYWORD)('None')