public function pushMessage($targetType, array $message, $requestId = null, $campaignKey = null)
    {
        return $this->pushMessages($targetType, [$message], $requestId, $campaignKey);
    }
public function pushMessage($targetType, array $message, $requestId = null, $campaignKey = null)
    {
        return $this->pushMessages($targetType, [$message], $requestId, $campaignKey);
    }
public function pushMessage ( $ targetType , array $ message , $ requestId = null , $ campaignKey = null ) { return $ this -> pushMessages ( $ targetType , [ $ message ] , $ requestId , $ campaignKey ) ; }
Send a single push notification message.

**Example**

```php
$message = [
'target' => [
'profile' => [
'criteria' => [
[
'key' => '$email',
'scope' => 'Organization',
'type' => 'string',
'op' => 'in',
'values' => [
'matthew@superbalist.com',
]
]
]
]
],
'alert' => [
'title' => 'Message Title',
'body' => 'This is my message content!',
],
];
$response = $localytics->pushMessage('profile', $message);

@param string $targetType (broadcast|customer_id|audience_id|profile)
@param array $message
@param string $requestId
@param string $campaignKey

@return array
Send a single push notification message .