code: func entitiesFieldRemove(field types.CustomFieldDef) {
  	entities := Map.All(field.ManagedObjectType)
  	for _, e := range entities {
  		entity := e.Entity()
  		Map.WithLock(entity, func() {
  			aFields := entity.AvailableField
  			for i, aField := range aFields {
  				if aField.Key == field.Key {
  					entity.AvailableField = append(aFields[:i], aFields[i+1:]...)
  					break
  				}
  			}
  
  			values := e.Entity().Value
  			for i, value := range values {
  				if value.(*types.CustomFieldStringValue).Key == field.Key {
  					entity.Value = append(values[:i], values[i+1:]...)
  					break
  				}
  			}
  
  			cValues := e.Entity().CustomValue
  			for i, cValue := range cValues {
  				if cValue.(*types.CustomFieldStringValue).Key == field.Key {
  					entity.CustomValue = append(cValues[:i], cValues[i+1:]...)
  					break
  				}
  			}
  		})
  	}
  }
docs: // Iterates through all entities of passed field type;
  // Removes found field from their custom field properties.