create an index from metada with GraphAware \ Neo4j \ OGM \ Annotations

Question

I'm using GraphAware\Neo4j\OGM\ for the management of nodes and relationships in Neo4j, to create the nodes I use the following metadata:

use GraphAware\Neo4j\OGM\Annotations as OGM;

    /**
     *
     * @OGM\Node(label="Contact")
     */
    class Contact 
    { ... }

in a cypher query it would be something like that

CREATE INDEX ON :Contact(firstname, email)