/// <summary>
/// Checks if the target of the invocation is an aggregate function.
/// </summary>
/// <param name="context">The query context used to resolve the routine.</param>
/// <returns>
/// Returns <c>true</c> if the target routine of the invocation is a <see cref="IFunction"/>
/// and the <see cref="IFunction.FunctionType"/> is <see cref="FunctionType.Aggregate"/>,
/// otherwise it returns <c>false</c>.
/// </returns>
public bool IsAggregate(IQueryContext context)
{
if (context.IsAggregateFunction(this))
return true;
// Look at parameterss
return Arguments.Any(x => x.HasAggregate(context));
}