visualization/visualization-model/src/main/java/se/jguru/nazgul/tools/visualization/model/diagram/statement/Statements.java
public Subgraph findSubgraph(final String identifier, final boolean recursive) {

        Optional<Subgraph> toReturn = getSubgraphs().stream().filter(c -> c.getId().equals(identifier)).findFirst();
        if (!toReturn.isPresent() && recursive && getSubgraphs() != null && !getSubgraphs().isEmpty()) {

            // Does the Node with the given identifier exist in any Subgraph?
            toReturn = getSubgraphs().stream()
                    .map(c -> c.getStatements().findSubgraph(identifier, true))
                    .filter(c -> c != null)
                    .findFirst();
        }

        // All Done.
        return toReturn.orElse(null);
    }
public Subgraph findSubgraph(final String identifier, final boolean recursive) {

        Optional<Subgraph> toReturn = getSubgraphs().stream().filter(c -> c.getId().equals(identifier)).findFirst();
        if (!toReturn.isPresent() && recursive && getSubgraphs() != null && !getSubgraphs().isEmpty()) {

            // Does the Node with the given identifier exist in any Subgraph?
            toReturn = getSubgraphs().stream()
                    .map(c -> c.getStatements().findSubgraph(identifier, true))
                    .filter(c -> c != null)
                    .findFirst();
        }

        // All Done.
        return toReturn.orElse(null);
    }
Finds the Subgraph with the supplied identifier within this Statements (and within any contained Subgraphs, if
the {@code recursive} flag is true).

@param identifier The identifier to match against the {@link Subgraph#getId()} of a matching Node.
@param recursive  If {@code true}, the search should recurse into the Statements of Subgraphs.
@return The Subgraph with the supplied identifier - or null if none was found.