/// <summary>
/// Logs a a diagnostic message based on the given warning code,
/// with the given source as the file for which the error occurred.
/// </summary>
public void Log(WarningCode code, IEnumerable <string> args, string source = null, LSP.Range range = null) =>
this.Log(new Diagnostic
{
Severity = DiagnosticSeverity.Warning,
Code = Warnings.Code(code),
Source = source,
Message = DiagnosticItem.Message(code, args ?? Enumerable.Empty <string>()),
Range = range
});