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+*Jump to [source](cargo-example-derive.rs)*
+
+For more on creating a custom subcommand, see [the cargo
+book](https://doc.rust-lang.org/cargo/reference/external-tools.html#custom-subcommands).
+The crate [`clap-cargo`](https://github.com/crate-ci/clap-cargo) can help in
+mimicking cargo's interface.
+
+The help looks like:
+```console
+$ cargo-example-derive --help
+cargo 
+
+USAGE:
+    cargo <SUBCOMMAND>
+
+OPTIONS:
+    -h, --help    Print help information
+
+SUBCOMMANDS:
+    example-derive    A simple to use, efficient, and full-featured Command Line Argument Parser
+    help              Print this message or the help of the given subcommand(s)
+
+$ cargo-example-derive example-derive --help
+cargo-example-derive [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    cargo example-derive [OPTIONS]
+
+OPTIONS:
+    -h, --help                             Print help information
+        --manifest-path <MANIFEST_PATH>    
+    -V, --version                          Print version information
+
+```
+
+Then to directly invoke the command, run:
+```console
+$ cargo-example-derive example-derive
+None
+
+$ cargo-example-derive example-derive --manifest-path Cargo.toml
+Some("Cargo.toml")
+
+```