code: private Map<String, URL> generateUmlDiagrams(PsiDocComment docComment) {
          TempFileManager tempFiles = Plugin.tempFileManager();
          Map<String, URL> urls = null;
          for ( PsiDocTag tag : docComment.getTags() ) {
              if ( tag instanceof PsiInlineDocTag ) {
                  continue;
              }
              else if ( tag.getName().equals("uml") || tag.getName().equals("startuml") ) {
                  if ( urls == null ) {
                      urls = new HashMap<>();
                  }
                  String text = stripLead(tag.getText());
                  text = stripFirstWord(text)[1];
                  String[] stripped = stripFirstWord(text);
                  String fileName = stripped[0];
                  text = stripped[1];
                  String plantUml = "@startuml " + fileName + "\n"
                          + "skinparam backgroundColor transparent\n"
                          + text
                          + "\n@enduml";
                  Plugin.print("UML Diagram Source", plantUml);
                  ByteArrayOutputStream image = new ByteArrayOutputStream();
                  try {
                      new SourceStringReader(plantUml).generateImage(image);
                  }
                  catch ( IOException e ) {
                      LOG.error("Error generating UML", e, fileName, String.valueOf(docComment.toString()), String.valueOf(docComment.getContainingFile()));
                  }
                  try {
                      urls.put(fileName, tempFiles.saveTempFile(image.toByteArray(), "png"));
                  }
                  catch ( IOException e ) {
                      LOG.error("Error generating UML", e, fileName, String.valueOf(docComment.toString()), String.valueOf(docComment.getContainingFile()));
                  }
              }
          }
          return MoreObjects.firstNonNull(urls, Collections.<String, URL>emptyMap());
      }
docs: Generates all PlantUML diagrams in the given `PsiDocComment`. It returns a Map of
  file names and the URLs where the image for that file has been saved to. Use this
  URL for the `<img>` tag.
  
  @param docComment    The `PsiDocComment`.
  
  @return A map mapping the file names to the image URLs.
  
  @see TempFileManager#saveTempFile(byte[], String)