code: public List<CompileEvent> getWarnings() {
          List<CompileEvent> warnings = new ArrayList<CompileEvent>();
          for (CompileEvent event : mIssues) {
              if (event.isWarning()) { warnings.add(event); }
          }
          
          return warnings;
      }
docs: Retrieves the set of warnings that were reported via the compileWarning
  method.
  
  @return a List of CompileEvent warning objects