@Override
    public boolean equals(final Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        final KeyedProperty<?> that = (KeyedProperty<?>) o;

        return key.equals(that.key);
    }
A utility implementation of a {@link Property} that only has a key but no value.

@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/util/keyed/KeyedProperty.java