SOURCE_FILE
  FN
    FN_KW "fn"
    WHITESPACE " "
    NAME
      IDENT "foo"
    PARAM_LIST
      L_PAREN "("
      R_PAREN ")"
    WHITESPACE " "
    BLOCK_EXPR
      STMT_LIST
        L_CURLY "{"
        WHITESPACE "\n    "
        LET_STMT
          LET_KW "let"
          WHITESPACE " "
          WILDCARD_PAT
            UNDERSCORE "_"
          WHITESPACE " "
          EQ "="
          WHITESPACE " "
          CALL_EXPR
            PATH_EXPR
              PATH
                PATH_SEGMENT
                  NAME_REF
                    IDENT "f"
            ARG_LIST
              L_PAREN "("
              R_PAREN ")"
          SEMICOLON ";"
        WHITESPACE "\n    "
        LET_STMT
          LET_KW "let"
          WHITESPACE " "
          WILDCARD_PAT
            UNDERSCORE "_"
          WHITESPACE " "
          EQ "="
          WHITESPACE " "
          CALL_EXPR
            CALL_EXPR
              CALL_EXPR
                PATH_EXPR
                  PATH
                    PATH_SEGMENT
                      NAME_REF
                        IDENT "f"
                ARG_LIST
                  L_PAREN "("
                  R_PAREN ")"
              ARG_LIST
                L_PAREN "("
                LITERAL
                  INT_NUMBER "1"
                R_PAREN ")"
            ARG_LIST
              L_PAREN "("
              LITERAL
                INT_NUMBER "1"
              COMMA ","
              WHITESPACE " "
              LITERAL
                INT_NUMBER "2"
              COMMA ","
              R_PAREN ")"
          SEMICOLON ";"
        WHITESPACE "\n    "
        LET_STMT
          LET_KW "let"
          WHITESPACE " "
          WILDCARD_PAT
            UNDERSCORE "_"
          WHITESPACE " "
          EQ "="
          WHITESPACE " "
          CALL_EXPR
            PATH_EXPR
              PATH
                PATH_SEGMENT
                  NAME_REF
                    IDENT "f"
            ARG_LIST
              L_PAREN "("
              CALL_EXPR
                PATH_EXPR
                  PATH
                    PATH
                      PATH_SEGMENT
                        L_ANGLE "<"
                        PATH_TYPE
                          PATH
                            PATH_SEGMENT
                              NAME_REF
                                IDENT "Foo"
                        R_ANGLE ">"
                    COLON2 "::"
                    PATH_SEGMENT
                      NAME_REF
                        IDENT "func"
                ARG_LIST
                  L_PAREN "("
                  R_PAREN ")"
              R_PAREN ")"
          SEMICOLON ";"
        WHITESPACE "\n    "
        EXPR_STMT
          CALL_EXPR
            PATH_EXPR
              PATH
                PATH_SEGMENT
                  NAME_REF
                    IDENT "f"
            ARG_LIST
              L_PAREN "("
              CALL_EXPR
                PATH_EXPR
                  PATH
                    PATH
                      PATH_SEGMENT
                        L_ANGLE "<"
                        PATH_TYPE
                          PATH
                            PATH_SEGMENT
                              NAME_REF
                                IDENT "Foo"
                        WHITESPACE " "
                        AS_KW "as"
                        WHITESPACE " "
                        PATH_TYPE
                          PATH
                            PATH_SEGMENT
                              NAME_REF
                                IDENT "Trait"
                        R_ANGLE ">"
                    COLON2 "::"
                    PATH_SEGMENT
                      NAME_REF
                        IDENT "func"
                ARG_LIST
                  L_PAREN "("
                  R_PAREN ")"
              R_PAREN ")"
          SEMICOLON ";"
        WHITESPACE "\n"
        R_CURLY "}"
  WHITESPACE "\n"
