JsonPathFile
  JsonPathRootSegmentImpl(ROOT_SEGMENT)
    PsiElement($)('$')
  PsiElement(.)('.')
  JsonPathFunctionCallImpl(FUNCTION_CALL)
    JsonPathIdImpl(ID)
      PsiElement(IDENTIFIER)('sum')
    PsiElement(()('(')
    JsonPathFunctionArgsListImpl(FUNCTION_ARGS_LIST)
      JsonPathPathExpressionImpl(PATH_EXPRESSION)
        JsonPathRootSegmentImpl(ROOT_SEGMENT)
          PsiElement($)('$')
        PsiElement(..)('..')
        JsonPathIdSegmentImpl(ID_SEGMENT)
          JsonPathIdImpl(ID)
            PsiElement(IDENTIFIER)('timestamp')
    PsiElement())(')')