SOURCE_FILE
  FN
    FN_KW "fn"
    WHITESPACE " "
    NAME
      IDENT "f"
    GENERIC_PARAM_LIST
      L_ANGLE "<"
      LIFETIME_PARAM
        LIFETIME
          LIFETIME_IDENT "'a"
        COLON ":"
        WHITESPACE " "
        TYPE_BOUND_LIST
          TYPE_BOUND
            LIFETIME
              LIFETIME_IDENT "'b"
      R_ANGLE ">"
    PARAM_LIST
      L_PAREN "("
      R_PAREN ")"
    WHITESPACE " "
    BLOCK_EXPR
      STMT_LIST
        L_CURLY "{"
        R_CURLY "}"
  WHITESPACE "\n"
