code: public boolean isEdge(final ODocument iRecord) {
      return iRecord != null ? iRecord.getSchemaClass().isSubClassOf(edgeBaseClass) : false;
    }
docs: Returns true if the document is an edge (its class is OGraphEdge or any subclasses)
  
  @param iRecord
  Document to analyze.
  @return true if the document is a edge (its class is OGraphEdge or any subclasses)