Function schema 

pub fn schema<T: SchemaEntrypoints + SchemaEvents + SchemaCustomTypes + SchemaErrors>(
    module_name: &str,
    contract_name: &str,
    contract_version: &str,
    authors: Vec<String>,
    repository: &str,
    homepage: &str,
) -> ContractSchema

Creates an instance of ContractSchema.

A contract schema is a representation of a smart contract’s schema. It includes information about the contract’s metadata, entrypoints, events, custom types, and errors.