Structure of the document:
CALL_EXPRESSION
  DOT_EXPRESSION
    NAME_EXPRESSION
      NAME
    NAME_EXPRESSION
      NAME
  PARAMS
    NAME_EXPRESSION
      NAME

CALL_EXPRESSION
  NAME_EXPRESSION
    NAME
  PARAMS
    NAME_EXPRESSION
      NAME

ASSIGNMENT_EXPRESSION
  NAME_EXPRESSION
    NAME
  NAME_EXPRESSION
    NAME