arangosh> var graph_module = require("org/arangodb/general-graph");
arangosh> graph_module._directedRelation("has_bought", ["Customer", "Company"], ["Groceries", "Electronics"]);
{ 
  "collection" : "has_bought", 
  "from" : [ 
    "Customer", 
    "Company" 
  ], 
  "to" : [ 
    "Groceries", 
    "Electronics" 
  ] 
}