arangosh&gt; <span class="hljs-keyword">var</span> rel = graph_module._relation(<span class="hljs-string">"isCustomer"</span>, [<span class="hljs-string">"shop"</span>], [<span class="hljs-string">"customer"</span>]);
arangosh&gt; graph._extendEdgeDefinitions(rel);
arangosh&gt; graph;
{[Graph] 
  <span class="hljs-string">"isCustomer"</span> : [ArangoCollection <span class="hljs-number">16601</span>, <span class="hljs-string">"isCustomer"</span> (type edge, status loaded)], 
  <span class="hljs-string">"shop"</span> : [ArangoCollection <span class="hljs-number">16593</span>, <span class="hljs-string">"shop"</span> (type <span class="hljs-built_in">document</span>, status loaded)], 
  <span class="hljs-string">"customer"</span> : [ArangoCollection <span class="hljs-number">16597</span>, <span class="hljs-string">"customer"</span> (type <span class="hljs-built_in">document</span>, status loaded)], 
  <span class="hljs-string">"pet"</span> : [ArangoCollection <span class="hljs-number">16586</span>, <span class="hljs-string">"pet"</span> (type <span class="hljs-built_in">document</span>, status loaded)] 
}