/**
* Adds new attribute to the entity. If attribute has no name, IllegalArgumentException is thrown.
*
* <p>Also sets <code>attr</code>'s entity to be this entity.
*/
public void addAttribute(Attribute attr) {
if (attr.getName() == null) {
throw new IllegalArgumentException("Attempt to insert unnamed attribute.");
}
attributes.put(attr.getName(), attr);
}
/** Adds new relationship to the entity. */
public void addRelationship(Relationship rel) {
relationships.put(rel.getName(), rel);
}
