1Parse a Rust source file into a `syn::File` and print out a debug representation 2of the syntax tree. 3 4Use the following command from this directory to test this program by running it 5on its own source code: 6 7``` 8cargo run -- src/main.rs 9``` 10 11The output will begin with: 12 13``` 14File { 15 shebang: None, 16 attrs: [ 17 Attribute { 18 pound_token: Pound, 19 style: Inner( 20 Bang 21 ), 22 bracket_token: Bracket, 23 path: Path { 24 leading_colon: None, 25 segments: [ 26 ... 27} 28``` 29