src/main/java/com/googlecode/objectify/impl/KeyMetadata.java
public void setLongId(P pojo, Long id) {
		if (!clazz.isAssignableFrom(pojo.getClass()))
			throw new IllegalArgumentException("Trying to use metadata for " + clazz.getName() + " to set key of " + pojo.getClass().getName());

		this.idMeta.getProperty().set(pojo, id);
	}
public void setLongId(P pojo, Long id) {
		if (!clazz.isAssignableFrom(pojo.getClass()))
			throw new IllegalArgumentException("Trying to use metadata for " + clazz.getName() + " to set key of " + pojo.getClass().getName());

		this.idMeta.getProperty().set(pojo, id);
	}
Sets the numeric id field