code: public String matchPattern(String alias) {
          // generate match pattern
          if (alias != null)
              return "(" + alias + processLabels(matchLabels, false) + ")";
          // pattern without alias
          return "(" + processLabels(matchLabels, false) + ")";
      }
docs: Generates a Cypher MATCH pattern for the vertex, example:
  <p>
  (alias:Label1:Label2)
  </p>
  
  @param alias The node alias, <code>null</code> if not required.
  @return the Cypher MATCH clause.