public static Expression <Func <T, bool> > AddWithAnd <T>(this Expression <Func <T, bool> > expr1, Expression <Func <T, bool> > expr2)
{
if (expr1 == null)
{
return(expr2);
}
var replacer = new ExpressionReplacer(CreateFromToReplaceSet(expr2.Parameters, expr1.Parameters), null, null, null, null);
var rightExpression = (LambdaExpression)replacer.HandleExpression(expr2);
return(Expression.Lambda <Func <T, bool> >
(Expression.AndAlso(expr1.Body, rightExpression.Body), expr1.Parameters));
}
