More standards

src/TrueSkill/Layers/IteratedTeamDifferencesInnerLayer.php

@@ -44,7 +44,7 @@ final class IteratedTeamDifferencesInnerLayer extends TrueSkillFactorGraphLayer
     }
 
     #[\Override]
-    public function createPriorSchedule(): ?ScheduleSequence
+    public function createPriorSchedule(): ScheduleSequence
     {
         switch (count($this->getInputVariablesGroups())) {
             case 0:

src/TrueSkill/Layers/PlayerPerformancesToTeamPerformancesLayer.php

@@ -34,7 +34,7 @@ final class PlayerPerformancesToTeamPerformancesLayer extends TrueSkillFactorGra
     }
 
     #[\Override]
-    public function createPriorSchedule(): ?ScheduleSequence
+    public function createPriorSchedule(): ScheduleSequence
     {
         $localFactors = $this->getLocalFactors();
 
@@ -69,7 +69,7 @@ final class PlayerPerformancesToTeamPerformancesLayer extends TrueSkillFactorGra
     }
 
     #[\Override]
-    public function createPosteriorSchedule(): ?ScheduleSequence
+    public function createPosteriorSchedule(): ScheduleSequence
     {
         $allFactors = [];
         $localFactors = $this->getLocalFactors();

src/TrueSkill/Layers/PlayerPriorValuesToSkillsLayer.php

@@ -51,7 +51,7 @@ final class PlayerPriorValuesToSkillsLayer extends TrueSkillFactorGraphLayer
     }
 
     #[\Override]
-    public function createPriorSchedule(): ?ScheduleSequence
+    public function createPriorSchedule(): ScheduleSequence
     {
         $localFactors = $this->getLocalFactors();
 

src/TrueSkill/Layers/PlayerSkillsToPerformancesLayer.php

@@ -53,7 +53,7 @@ final class PlayerSkillsToPerformancesLayer extends TrueSkillFactorGraphLayer
     }
 
     #[\Override]
-    public function createPriorSchedule(): ?ScheduleSequence
+    public function createPriorSchedule(): ScheduleSequence
     {
         $localFactors = $this->getLocalFactors();
 
@@ -68,7 +68,7 @@ final class PlayerSkillsToPerformancesLayer extends TrueSkillFactorGraphLayer
     }
 
     #[\Override]
-    public function createPosteriorSchedule(): ?ScheduleSequence
+    public function createPosteriorSchedule(): ScheduleSequence
     {
         $localFactors = $this->getLocalFactors();