src/main/java/com/github/fge/grappa/matchers/base/AbstractMatcher.java
@Override
    public <V> MatcherContext<V> getSubContext(final MatcherContext<V> context)
    {
        return context.getSubContext(this);
    }
@Override
    public <V> MatcherContext<V> getSubContext(final MatcherContext<V> context)
    {
        return context.getSubContext(this);
    }
default implementation is to simply delegate to the context