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    //! Dummy implementations that we emit along with an error.

    use proc_macro2::Ident;
    use proc_macro_error::append_dummy;
    use quote::quote;

    pub fn parser_struct(name: &Ident) {
        into_app(name);
        args(name);
        append_dummy(quote!( impl clap::Parser for #name {} ));
    }

    pub fn parser_enum(name: &Ident) {
        into_app(name);
        subcommand(name);
        append_dummy(quote!( impl clap::Parser for #name {} ));
    }

    pub fn into_app(name: &Ident) {
        append_dummy(quote! {
            impl clap::CommandFactory for #name {
                fn command<'b>() -> clap::Command {
                    unimplemented!()
                }
                fn command_for_update<'b>() -> clap::Command {
                    unimplemented!()
                }
            }
        });
    }

    pub fn from_arg_matches(name: &Ident) {
        append_dummy(quote! {
            impl clap::FromArgMatches for #name {
                fn from_arg_matches(_m: &clap::ArgMatches) -> ::std::result::Result<Self, clap::Error> {
                    unimplemented!()
                }
                fn update_from_arg_matches(&mut self, matches: &clap::ArgMatches) -> ::std::result::Result<(), clap::Error>{
                    unimplemented!()
                }
            }
        });
    }

    pub fn subcommand(name: &Ident) {
        from_arg_matches(name);
        append_dummy(quote! {
            impl clap::Subcommand for #name {
                fn augment_subcommands(_cmd: clap::Command) -> clap::Command {
                    unimplemented!()
                }
                fn augment_subcommands_for_update(_cmd: clap::Command) -> clap::Command {
                    unimplemented!()
                }
                fn has_subcommand(name: &str) -> bool {
                    unimplemented!()
                }
            }
        });
    }

    pub fn args(name: &Ident) {
        from_arg_matches(name);
        append_dummy(quote! {
            impl clap::Args for #name {
                fn augment_args(_cmd: clap::Command) -> clap::Command {
                    unimplemented!()
                }
                fn augment_args_for_update(_cmd: clap::Command) -> clap::Command {
                    unimplemented!()
                }
            }
        });
    }

    pub fn value_enum(name: &Ident) {
        append_dummy(quote! {
            impl clap::ValueEnum for #name {
                fn value_variants<'a>() -> &'a [Self]{
                    unimplemented!()
                }
                fn from_str(_input: &str, _ignore_case: bool) -> ::std::result::Result<Self, String> {
                    unimplemented!()
                }
                fn to_possible_value<'a>(&self) -> ::std::option::Option<clap::builder::PossibleValue>{
                    unimplemented!()
                }
            }
        })
    }