private Assembly CompileAssembly(Node node, string url, CompilerErrorCollection errors)
 {
     CompilerContext oldContext = Context;
     CompilerContext result = Compile(url);
     _context = oldContext;
     if (result.Errors.Count > 0)
     {
         errors.Add(new CompilerError(node.LexicalInfo, "Failed to add a file reference"));
         foreach (CompilerError err in result.Errors)
         {
             errors.Add(err);
         }
         return null;
     }
     return result.GeneratedAssembly;
 }
        public bool GetNode(Expression expression, bool asAttribute,
		                    CompilerErrorCollection compileErrors)
        {
            _isAttribute = asAttribute;
            _compileErrors = compileErrors;

            Visit(expression);

            if (_node == null)
            {
                _compileErrors.Add(CompilerErrorFactory.CustomError(expression.LexicalInfo,
                    "Unrecgonized configuration node syntax"));
                return false;
            }

            return true;
        }