Instance function retrieves Convertor singleton instance.

ErrMapKeyNotString error is returned when some map has keys with type different from string.

ErrMismatchedTypes error is returned when types of input and output fields doesn't match.

ErrOutputNotPointer error is returned when provided output parameter is not a pointer.

ErrUnknownField error is returned when output structure doesn't have an appropriate field for input data.

ErrUnsupportedType error is returned when source contains data of type unsupported by this package.

Convertor structure that provides converting functionality.