@Override
  public boolean supports(Class<?> authentication) {
    return UsernamePasswordAuthenticationToken.class.isAssignableFrom(authentication);
  }
Perform the OS-level PAM authentication routine.

@param ambariUsername the Ambari username, used for logging and notifications
@param localUsername  the username to use for authenticating
@param password       the password to use for authenticating
@return the resulting user object
ambari-server/src/main/java/org/apache/ambari/server/security/authentication/pam/AmbariPamAuthenticationProvider.java