[TASK] Add native type declarations for Import

CHANGELOG.md

@@ -34,7 +34,7 @@ Please also have a look at our
 - Use more native type declarations and strict mode
   (#641, #772, #774, #778, #804, #841, #873, #875, #891, #922, #923, #933, #958,
   #964, #967, #1000, #1044, #1134, #1136, #1137, #1139, #1140, #1141, #1145,
-  #1162, #1163, #1166)
+  #1162, #1163, #1166, #1172)
 - Add visibility to all class/interface constants (#469)
 
 ### Deprecated

config/phpstan-baseline.neon

@@ -72,12 +72,6 @@ parameters:
 			count: 1
 			path: ../src/Property/Charset.php
 
-		-
-			message: '#^Only booleans are allowed in an if condition, string given\.$#'
-			identifier: if.condNotBoolean
-			count: 1
-			path: ../src/Property/Import.php
-
 		-
 			message: '#^Only booleans are allowed in an if condition, Sabberworm\\CSS\\Value\\RuleValueList\|string\|null given\.$#'
 			identifier: if.condNotBoolean

src/Property/Import.php

@@ -19,7 +19,7 @@ class Import implements AtRule
     private $location;
 
     /**
-     * @var string
+     * @var string|null
      */
     private $mediaQuery;
 
@@ -38,10 +38,9 @@ class Import implements AtRule
     protected $comments = [];
 
     /**
-     * @param string $mediaQuery
      * @param int<0, max> $lineNumber
      */
-    public function __construct(URL $location, $mediaQuery, int $lineNumber = 0)
+    public function __construct(URL $location, ?string $mediaQuery, int $lineNumber = 0)
     {
         $this->location = $location;
         $this->mediaQuery = $mediaQuery;
@@ -56,18 +55,12 @@ public function getLineNo(): int
         return $this->lineNumber;
     }
 
-    /**
-     * @param URL $location
-     */
-    public function setLocation($location): void
+    public function setLocation(URL $location): void
     {
         $this->location = $location;
     }
 
-    /**
-     * @return URL
-     */
-    public function getLocation()
+    public function getLocation(): URL
     {
         return $this->location;
     }
@@ -95,14 +88,15 @@ public function atRuleName(): string
     }
 
     /**
-     * @return array<int, URL|string>
+     * @return array{0: URL, 1?: non-empty-string}
      */
     public function atRuleArgs(): array
     {
         $result = [$this->location];
-        if ($this->mediaQuery) {
-            \array_push($result, $this->mediaQuery);
+        if (\is_string($this->mediaQuery) && $this->mediaQuery !== '') {
+            $result[] = $this->mediaQuery;
         }
+
         return $result;
     }
 
@@ -130,10 +124,7 @@ public function setComments(array $comments): void
         $this->comments = $comments;
     }
 
-    /**
-     * @return string
-     */
-    public function getMediaQuery()
+    public function getMediaQuery(): ?string
     {
         return $this->mediaQuery;
     }