================================================================================
Simple expression list
================================================================================
a, b
--------------------------------------------------------------------------------

(source_file
  (simple_statement
    (expression_list
      (reference_expression
        (identifier))
      (reference_expression
        (identifier)))))

================================================================================
Expression list inside if
================================================================================
if s.no_inner {
    return '!'
}
--------------------------------------------------------------------------------

(source_file
  (simple_statement
    (if_expression
      (selector_expression
        (reference_expression
          (identifier))
        (reference_expression
          (identifier)))
      (block
        (return_statement
          (expression_list
            (literal
              (interpreted_string_literal))))))))
