Is your feature request related to a problem? Please describe.

Generated code is not compatible with Rust 2018+ edition. If edition = "2018" is added in Cargo.toml, code fails to compile.

Describe the solution you'd like

Compilation errors are related to imports. Imports starting with :: (::models, ::apis) prefix must be prefixed with "crate::" (crate::models, crate::apis).

Note : this replacement is backward compatible.

Describe alternatives you've considered

Additional context