public String getSecurityManagerName() {
        return securityManagerName;
    }
Returns the name of the {@link SecurityManager} instance in the backing map.  Used as a key to lookup the
instance.  Unless set otherwise, the default is {@code securityManager}.

@return the name of the {@link SecurityManager} instance in the backing map.  Used as a key to lookup the
instance.
core/src/main/java/org/apache/shiro/env/DefaultEnvironment.java