code: func (m Map) Merge(m2 Map) {
  	for _, prefix := range m2.Keys() {
  		m.Delete(prefix)
  
  		for k, v := range m2 {
  			if strings.HasPrefix(k, prefix) {
  				m[k] = v
  			}
  		}
  	}
  }
docs: // Merge merges the contents of the other Map into this one.
  //
  // This merge is smarter than a simple map iteration because it
  // will fully replace arrays and other complex structures that
  // are present in this map with the other map's. For example, if
  // this map has a 3 element "foo" list, and m2 has a 2 element "foo"
  // list, then the result will be that m has a 2 element "foo"
  // list.