src/main/java/com/googlecode/objectify/impl/Registrar.java
public <T> EntityMetadata<T> getMetadataSafe(String kind) throws IllegalArgumentException {
		EntityMetadata<T> metadata = this.getMetadata(kind);
		if (metadata == null)
			throw new IllegalArgumentException("No entity class has been registered which matches kind '" + kind + "'");
		else
			return metadata;
	}
public <T> EntityMetadata<T> getMetadataSafe(String kind) throws IllegalArgumentException {
		EntityMetadata<T> metadata = this.getMetadata(kind);
		if (metadata == null)
			throw new IllegalArgumentException("No entity class has been registered which matches kind '" + kind + "'");
		else
			return metadata;
	}
Gets metadata for the specified kind
@throws IllegalArgumentException if the kind has not been registered