code: public static Concatenator existsPattern(IElement X) {
  		Concatenator ret = P.existsPattern(X);
  		ASTNode an = APIObjectAccess.getAstNode(ret);
  		an.setClauseType(ClauseType.WHERE);
  		return ret;
  	}
docs: <div color='red' style="font-size:24px;color:red"><b><i><u>JCYPHER</u></i></b></div>
  <div color='red' style="font-size:18px;color:red"><i>matches a pattern expression against the graph. If the result is empty, returns false, else returns true</i></div>
  <div color='red' style="font-size:18px;color:red"><i>Use Factory Class <b>X</b> to create Expressions</i></div>
  <div color='red' style="font-size:18px;color:red"><i>e.g. ...<b>existsPattern(X</b>.node(n)...)</i></div>
  <br/>