title: How to retrieve a specific relationship by one of its properties in Cypher? (neo4j)
body: <p>I am trying to come up with the Cypher syntax to both:</p>
  
  <ul>
  <li>Create an index on a relationship property </li>
  <li>Query that index in order to retrieve an specific relationship from one of its values.</li>
  </ul>
  
  <p>Since labels cannot be used for relationships, how could it be done?</p>