code: func (c ConversionFuncs) Merge(other ConversionFuncs) ConversionFuncs {
  	merged := NewConversionFuncs()
  	for k, v := range c.fns {
  		merged.fns[k] = v
  	}
  	for k, v := range other.fns {
  		merged.fns[k] = v
  	}
  	return merged
  }
docs: // Merge returns a new ConversionFuncs that contains all conversions from
  // both other and c, with other conversions taking precedence.