code: public OGraphVertex unlink(final OGraphVertex iTargetVertex) {
  		if (iTargetVertex == null)
  			throw new IllegalArgumentException("Missed the target vertex");
  
  		unlink(database, document, iTargetVertex.getDocument());
  
  		return this;
  	}
docs: Remove the link between the current vertex and the target one.
  
  @param iTargetVertex
  Target vertex where to remove the connection
  @return Current vertex (useful for fluent calls)