* @return coalesce expression
*/
public <Y> Expression<Y> coalesce(Expression<? extends Y> x, Y y){
ArgumentListFunctionExpression coalesce = ((InternalSelection)x).getCurrentNode().coalesce();
coalesce.addChild(((InternalSelection)x).getCurrentNode());
coalesce.addChild(((InternalSelection)y).getCurrentNode());
return new CoalesceImpl(metamodel, x.getJavaType(), coalesce, buildList(x, literal(y)), "coalesce");
}
/**
* Create an expression that tests whether its argument are equal, returning