This module provides an API to link filter nodes using the logic configured in
'policy.conf'. This configuration file allows grouping filters together (sorted
by priority) to use a common target node. A node is considered a filter node if
it has the node.link-group property.

By default, all echo-cancel, filter-chain and loopback filters with default
names will be linked with the default input/output devcie. Any other filters
that do not have a default name will be treated as a regular node.