code: func cloneField(field *ObjectField) {
  	if field.Method != nil {
  		field.Method = Clone(field.Method).(*Function)
  	}
  
  	oldParams := field.Params
  	if oldParams != nil {
  		field.Params = new(Parameters)
  		*field.Params = *oldParams
  	}
  	cloneParameters(field.Params)
  
  	clone(&field.Expr1)
  	clone(&field.Expr2)
  	clone(&field.Expr3)
  }
docs: // Updates fields of field to point to deep clones.