roots property

Iterable<E> roots

Each node that is exposed as a root node of the walkable collection.

A root node is implementation defined, but is typically a node that has one or more successors, but not necessarily. For example, a graph may have multiple root nodes, or choose to expose every node in the graph as a root node, while a tree may have only one root node.

A collection that has no root nodes is considered empty.

Implementation

Iterable<E> get roots;