code: public static DotLexer createLexer(final InputStream dotDiagramData) {
  
          // Check sanity
          if (dotDiagramData == null) {
              throw new IllegalArgumentException("Cannot handle null 'dotDiagramData' argument.");
          }
  
          try {
  
              // All Done.
              return new DotLexer(new ANTLRInputStream(dotDiagramData));
          } catch (IOException e) {
              throw new IllegalArgumentException("Could not create DotLexer", e);
          }
      }
docs: Factory method creating a DotLexer from the supplied InputStream, assumed to contain Graphviz/DOT diagram data.
  
  @param dotDiagramData The InputStream containing Graphviz/DOT data, complying
  with <a href="http://www.graphviz.org/content/dot-language">DOT language specification</a>.
  @return A {@link DotLexer} using the supplied InputStream as source of tokens.