Fix: Describe iterable type

Author: localheinz

src/Data/ProcessedCodeCoverageData.php

@@ -124,11 +124,17 @@ public function lineCoverage(): array
         return $this->lineCoverage;
     }
 
+    /**
+     * @param FunctionCoverageType $functionCoverage
+     */
     public function setFunctionCoverage(array $functionCoverage): void
     {
         $this->functionCoverage = $functionCoverage;
     }
 
+    /**
+     * @return FunctionCoverageType
+     */
     public function functionCoverage(): array
     {
         ksort($this->functionCoverage);