| DuplicateEdgeException | Thrown when the Edge is not multiplicable, and there's an attempt to create it multiple times. |
| EdgeAlreadyConnectedException | Thrown when the Edge is not orphan and there's an attempt to reconnect it via the ```connect``` method. |
| InvalidDirectionException | Thrown when the given Direction is not valid. |
| InvalidEncapsulatedEdgeException | Thrown when the data source does not conform with EncapsulatedEdge standards. |
| MalformedIDException | Thrown when the given ID is not a valid Pho ID. |
| NodeAlreadyMemberException | Thrown when the node is already a member of the given graph. |
| NodeDoesNotExistException | Thrown when the given node is not present. |
| OrphanEdgeException | Thrown when an orphan edge has called for an operation that requires a head node to exist. |