CDI 1.1

5.4.1 Client proxy invocation

"The behavior of all methods declared by java.lang.Object, except for toString(), is undefined for a client proxy.
Portable applications should not invoke any method declared by java.lang.Object, except for toString(), on a client
proxy."

EJB 3.2

3.4.7Session Object Identity

"A client can test two EJB 3.x remote or local view references for identity by means of the Object.equals and Object.hashCode methods."

Subsections define it further.