diff --git a/Http/Http.php b/Http/Http.php
index 22febc4..a24ba17 100644
--- a/Http/Http.php
+++ b/Http/Http.php
@@ -22,44 +22,14 @@
  */
 class Http
 {
-    /**
-     * @var string
-     *
-     * Token query param field
-     */
     const TOKEN_FIELD = 'token';
-
-    /**
-     * @var string
-     *
-     * Changes query param field
-     */
     const CHANGES_FIELD = 'changes';
-
-    /**
-     * @var string
-     *
-     * Query query param field
-     */
     const QUERY_FIELD = 'query';
 
-    /**
-     * @var string
-     *
-     * App ID Header
-     */
     const APP_ID_HEADER = 'APISEARCH-APP-ID';
-
-    /**
-     * @var string
-     *
-     * Token ID Header
-     */
     const TOKEN_ID_HEADER = 'APISEARCH-TOKEN-ID';
 
     /**
-     * Get common query values.
-     *
      * @param RepositoryWithCredentials $repository
      *
      * @return string[]
diff --git a/Query/Query.php b/Query/Query.php
index 8567d32..c827d33 100644
--- a/Query/Query.php
+++ b/Query/Query.php
@@ -250,7 +250,7 @@ public static function createLocated(
         int $page = self::DEFAULT_PAGE,
         int $size = self::DEFAULT_SIZE
     ) {
-        $query = self::create(
+        $query = static::create(
             $queryText,
             $page,
             $size
@@ -291,7 +291,7 @@ public static function create(
      */
     public static function createMatchAll(): self
     {
-        return self::create(
+        return static::create(
             '',
             self::DEFAULT_PAGE,
             self::DEFAULT_SIZE
@@ -307,7 +307,7 @@ public static function createMatchAll(): self
      */
     public static function createByUUID(ItemUUID $uuid): self
     {
-        return self::createByUUIDs([$uuid]);
+        return static::createByUUIDs([$uuid]);
     }
 
     /**
@@ -323,7 +323,7 @@ public static function createByUUIDs(array $uuids): self
             return $uuid->composeUUID();
         }, $uuids);
 
-        $query = self::create('', self::DEFAULT_PAGE, count($uuids))
+        $query = static::create('', self::DEFAULT_PAGE, count($uuids))
             ->disableAggregations()
             ->disableSuggestions();
 
@@ -1546,16 +1546,16 @@ public function toArray(): array
     public static function createFromArray(array $array): self
     {
         $query = isset($array['coordinate'])
-            ? self::createLocated(
+            ? static::createLocated(
                 Coordinate::createFromArray($array['coordinate']),
                 $array['q'] ?? '',
-                (int) ($array['page'] ?? self::DEFAULT_PAGE),
-                (int) ($array['size'] ?? self::DEFAULT_SIZE)
+                (int) ($array['page'] ?? static::DEFAULT_PAGE),
+                (int) ($array['size'] ?? static::DEFAULT_SIZE)
             )
-            : self::create(
+            : static::create(
                 $array['q'] ?? '',
-                (int) ($array['page'] ?? self::DEFAULT_PAGE),
-                (int) ($array['size'] ?? self::DEFAULT_SIZE)
+                (int) ($array['page'] ?? static::DEFAULT_PAGE),
+                (int) ($array['size'] ?? static::DEFAULT_SIZE)
             );
         $query->fields = $array['fields'] ?? [];
         $query->aggregations = array_map(function (array $aggregation) {
@@ -1587,7 +1587,7 @@ public static function createFromArray(array $array): self
         $query->scoreStrategies = isset($array['score_strategies'])
             ? ScoreStrategies::createFromArray($array['score_strategies'])
             : null;
-        $query->minScore = $array['min_score'] ?? self::NO_MIN_SCORE;
+        $query->minScore = $array['min_score'] ?? static::NO_MIN_SCORE;
         $query->metadata = $array['metadata'] ?? [];
 
         if (isset($array['user'])) {
diff --git a/composer.json b/composer.json
index 51aec9a..d381fc1 100644
--- a/composer.json
+++ b/composer.json
@@ -10,7 +10,7 @@
         }
     ],
     "require": {
-        "php": ">=7.1",
+        "php": ">=7.2",
         "ext-curl": "*",
         "symfony/event-dispatcher": "^3.4 || ^4.0 || ^5.0",
         "symfony/yaml": "^3.4 || ^4.0 || ^5.0",