function keepOrDestroy(iBase, oContext0, iIndex) {
			if (oContext0.created()) { // e.g. Recursive Hierarchy maintenance
				aContexts.push(oContext0);
				iNewLength = iBase + iIndex + 1;
			} else {
				delete this.aContexts[iBase + iIndex];
				this.destroyLater(oContext0);
			}
		}
Keeps and requests created contexts, destroys others.

@param {number} iBase - A base index
@param {sap.ui.model.odata.v4.Context} oContext0 - A context, maybe created
@param {number} iIndex - A relative index