function checkSelectionCount(assert, oListBinding) {
		if (!oListBinding.getHeaderContext().isSelected()) {
			assert.strictEqual(oListBinding.getSelectionCount(),
				oListBinding._getAllExistingContexts()
					.filter((oContext0) => oContext0.isSelected())
					.length,
				"$selectionCount vs. filtering");
		} // else: "select all" currently unsupported
	}
Checks the given list binding's selection count versus the selection state of its existing
contexts.

@param {object} assert - The QUnit assert object
@param {sap.ui.model.odata.v4.ODataListBinding} oListBinding - A list binding