PyFile:EmptySubscription.py
  PyAssignmentStatement
    PyTargetExpression: s
      PsiElement(Py:IDENTIFIER)('s')
    PsiWhiteSpace(' ')
    PsiElement(Py:EQ)('=')
    PsiWhiteSpace(' ')
    PySubscriptionExpression
      PyStringLiteralExpression: 
        PsiElement(Py:SINGLE_QUOTED_STRING)('''')
      PsiElement(Py:LBRACKET)('[')
      PsiErrorElement:expression expected
        <empty list>
      PsiElement(Py:RBRACKET)(']')