public QueryTranslator([NotNull] IQueryable source, [NotNull] Expression expression, [NotNull] IEnumerable <ExpressionVisitor> visitors)
 {
     Expression = expression;
     _provider  = new QueryTranslatorProvider <T>(source, visitors);
 }
 public QueryTranslator([NotNull] IQueryable source, [NotNull] IEnumerable <ExpressionVisitor> visitors)
 {
     Expression = Expression.Constant(this);
     _provider  = new QueryTranslatorProvider <T>(source, visitors);
 }