title: How to provide fix for all parameters of the method (Roslyn - FixProvider)
body: <p>I wrote code analyzer &amp; fix provider for adding validations to ensure argument is not null. It works good for multiple methods, but I cannot check all the parameters at once. The analyzer will mark all the parameters that are not checked already, but fix can be done only for one parameter at once.</p>
  
  <p><strong>Details:</strong>
  It is not immutable nodes issue, the code adds using statement if needed. </p>
  
  <p>In the analyzer i register diagnostic for every parameter.</p>
  
  <pre><code>  Diagnostic diagnostic = Diagnostic.Create(
                      Rule,
                      parameter.GetLocation(),
                      null,
                      prop.ToImmutableDictionary(),
                      parameter.Identifier.Text);
  </code></pre>
  
  <p>In the fix provider I am taking first diagnostic from the context and register code fix for that. </p>
  
  <p>Maybe I am doing something wrong and thus do not get multiple diagnostics in the fix provider.</p>
  
  <p>What is the correct way to make multiple fixes? Should be the key/id of the diagnostic the same? Or should the diagnostic be registered directly to complain about all the parameters.</p>