code: func WithIdentityConfig(identityConfigs ...interface{}) Option {
  	return func(opts *options) error {
  		c, err := mspImpl.BuildIdentityConfigFromOptions(identityConfigs...)
  		if err != nil {
  			return err
  		}
  		opts.IdentityConfig = c
  		return nil
  	}
  }
docs: // WithIdentityConfig injects a IdentityConfig interface to the SDK
  // it accepts either a full interface of IdentityConfig or a list
  // of sub interfaces each implementing one (or more) function(s) of IdentityConfig