Implementation of an edge representing a foreign key (FK) relationship between two
tables.
The from node is the table which have the FK, while the
to node is the table with the PK.
ISearchCallback implementation that get the nodes using both direct and reverse
foreign key dependency, i.e, if table C has a FK for a table A and table A has
a FK for a table B, then getNodes(A) will return B and C.
ISearchCallback implementation that get the nodes using direct foreign key
dependency, i.e, if table A has a FK for a table B, then getNodes(A) will
return B.