SOURCE_FILE
  USE
    USE_KW "use"
    WHITESPACE " "
    USE_TREE
      PATH
        PATH
          PATH_SEGMENT
            NAME_REF
              CRATE_KW "crate"
        COLON2 "::"
        PATH_SEGMENT
          NAME_REF
            IDENT "foo"
    SEMICOLON ";"
  WHITESPACE "\n"
