# Interface ToManyMapProperty

All Superinterfaces:
  `ArcProperty, PropertyDescriptor, ToManyProperty`

public interface ToManyMapProperty extends ToManyProperty
A property representing a map of objects keyed by one of the object properties.

Since:
  3.0

- ## Method Summary

  Modifier and Type
  Method
  Description
  `Object`
  `getMapKey(Object target)`
  Extracts the map key of the target object.

  ### Methods inherited from interface ArcProperty

  `getComplimentaryReverseArc, getComplimentaryReverseDbRelationshipPath, getRelationship, getTargetDescriptor, invalidate, isFault`

  ### Methods inherited from interface PropertyDescriptor

  `equals, getName, injectValueHolder, readProperty, readPropertyDirectly, visit, writeProperty, writePropertyDirectly`

  ### Methods inherited from interface ToManyProperty

  `addTarget, addTargetDirectly, removeTarget, removeTargetDirectly`

- ## Method Details

  - ### getMapKey

    Object getMapKey(Object target) throws PropertyException
    Extracts the map key of the target object.
    Throws:
      `PropertyException`