Improve Node.hasProperty/getProperty and Node.hasNode/getNode combinations

In many applications using JCR I see this pattern:

if (jcrNode.hasProperty(PROP) {
  value = jcrNode.getProperty(PROP);
}

I checked the implementation behind and found that Oak's NodeImpl implements hasProperty almost identical to the getProperty with

node.getPropertyOrNull(oakPath) != null;

That means that the above mentioned JCR code snippet invokes node.getPropertyOrNull twice. This could be improved by exposing a new method getPropertyOrNull, in which the above code could be written like this:

tmpProp = jcrNode.getPropertyOrNull(PROP);
if (tmpProp != null) {
  value = tmpProp;
}

In this case there just the jcrNode.getPropertyOrNull method would do a single call into call, saving us the overhead of a second if the property is there.

Of course this cannot go into the JCR Node interface, but we could extend the JackrabbitNode with this.