SOURCE_FILE
  MACRO_RULES
    COMMENT "// 2015"
    WHITESPACE "\n"
    MACRO_RULES_KW "macro_rules"
    BANG "!"
    WHITESPACE " "
    NAME
      IDENT "try"
    WHITESPACE " "
    TOKEN_TREE
      L_CURLY "{"
      WHITESPACE " "
      TOKEN_TREE
        L_PAREN "("
        R_PAREN ")"
      WHITESPACE " "
      EQ "="
      R_ANGLE ">"
      WHITESPACE " "
      TOKEN_TREE
        L_CURLY "{"
        R_CURLY "}"
      WHITESPACE " "
      R_CURLY "}"
  WHITESPACE "\n"
