PyiFile:Simple.pyi
  PyFunction('foo')
    PsiElement(Py:DEF_KEYWORD)('def')
    PsiWhiteSpace(' ')
    PsiElement(Py:IDENTIFIER)('foo')
    PyParameterList
      PsiElement(Py:LPAR)('(')
      PyNamedParameter('x')
        PsiElement(Py:IDENTIFIER)('x')
        PyAnnotation
          PsiElement(Py:COLON)(':')
          PsiWhiteSpace(' ')
          PyReferenceExpression: int
            PsiElement(Py:IDENTIFIER)('int')
      PsiElement(Py:RPAR)(')')
    PsiWhiteSpace(' ')
    PyAnnotation
      PsiElement(Py:RARROW)('->')
      PsiWhiteSpace(' ')
      PyReferenceExpression: int
        PsiElement(Py:IDENTIFIER)('int')
    PsiElement(Py:COLON)(':')
    PsiWhiteSpace(' ')
    PyStatementList
      PyExpressionStatement
        PyNoneLiteralExpression
          PsiElement(Py:DOT)('.')
          PsiElement(Py:DOT)('.')
          PsiElement(Py:DOT)('.')