function setPostBodyCollection() {
			aElements.$postBodyCollection = oPostBody[sName] = aPostBodyCollection;
		}
Adds a collection below a transient element.

@param {string} sPath
  The collection path
@param {string[]} [aSelect]
  The binding's $select if it would create a cache; later used for updateSelected (either
  taking this aSelect or calculating it from the path)
@returns {object[]}
  The elements collection (either from the initial data or empty)
@throws {Error} If the cache is shared

@public