public function testGetCredentialsField()
 {
     $usernameField = 'foo';
     $passwordField = 'bar';
     $credentialsFields = ['username' => $usernameField, 'password' => $passwordField];
     $this->baseLdapUserProvider->setCredentialsFields($credentialsFields);
     $this->assertEquals($usernameField, $this->baseLdapUserProvider->getCredentialsField('username'));
     $this->assertEquals($passwordField, $this->baseLdapUserProvider->getCredentialsField('password'));
 }