AlphaNodes are nodes in the Rete network used
to apply FieldConstraint<.code>s on asserted fact
objects where the FieldConstraints have no dependencies on any other of the facts in the current Rule.
Intermediate class to have a workaround for *Node default visibility
and ReteooVisitor.
It's not good to have
GraphicalVertex dependency in
org.drools.reteoo package.
All asserting Facts must propagated into the right ObjectSink side of a BetaNode, if this is the first Pattern
then there are no BetaNodes to propagate to.
ObjectTypeNodes are responsible for filtering and propagating the matching
fact assertions propagated from the Rete node using ObjectType interface.
The assert and retract methods do not attempt to filter as this is the role of the Rete
node which builds up a cache of matching ObjectTypdeNodess for each asserted object, using
the matches(Object object) method.
When joining a subnetwork into the main network again, RightInputAdapterNode adapts the
subnetwork's tuple into a fact in order right join it with the tuple being propagated in
the main network.