function PresenterContext(aAccessible, aOldAccessible) {
  this._accessible = aAccessible;
  this._oldAccessible =
    this._isDefunct(aOldAccessible) ? null : aOldAccessible;
}
/**
 * PresenterContext: An object that generates and caches context information
 * for a given accessible and its relationship with another accessible.
 */
An object that generates and caches context information
for a given accessible and its relationship with another accessible.
An object that generates and caches context information for a given accessible and its relationship with another accessible .
function PresenterContext(aAccessible, aOldAccessible) {
  this._accessible = aAccessible;
  this._oldAccessible =
    this._isDefunct(aOldAccessible) ? null : aOldAccessible;
}
function PresenterContext ( aAccessible , aOldAccessible ) { this . _accessible = aAccessible ; this . _oldAccessible = this . _isDefunct ( aOldAccessible ) ? null : aOldAccessible ; }
PresenterContext: An object that generates and caches context information
 for a given accessible and its relationship with another accessible.
PresenterContext : An object that generates and caches context information for a given accessible and its relationship with another accessible .