code: func (s *Scheme) RegisterInputDefaults(in interface{}, fn conversion.FieldMappingFunc, defaultFlags conversion.FieldMatchingFlags) error {
  	return s.converter.RegisterInputDefaults(in, fn, defaultFlags)
  }
docs: // RegisterInputDefaults sets the provided field mapping function and field matching
  // as the defaults for the provided input type.  The fn may be nil, in which case no
  // mapping will happen by default. Use this method to register a mechanism for handling
  // a specific input type in conversion, such as a map[string]string to structs.