SOURCE_FILE
  IMPL
    IMPL_KW "impl"
    WHITESPACE " "
    PATH_TYPE
      PATH
        PATH_SEGMENT
          NAME_REF
            IDENT "T"
    WHITESPACE " "
    FOR_KW "for"
    WHITESPACE " "
    PATH_TYPE
      PATH
        PATH_SEGMENT
          NAME_REF
            IDENT "Foo"
    WHITESPACE " "
    ASSOC_ITEM_LIST
      L_CURLY "{"
      WHITESPACE "\n    "
      FN
        DEFAULT_KW "default"
        WHITESPACE " "
        ASYNC_KW "async"
        WHITESPACE " "
        FN_KW "fn"
        WHITESPACE " "
        NAME
          IDENT "foo"
        PARAM_LIST
          L_PAREN "("
          R_PAREN ")"
        WHITESPACE " "
        BLOCK_EXPR
          STMT_LIST
            L_CURLY "{"
            R_CURLY "}"
      WHITESPACE "\n"
      R_CURLY "}"
  WHITESPACE "\n"
