Fix bug introduced with f19a148c

theodolite/src/main/kotlin/rocks/theodolite/core/strategies/restrictionstrategy/LowerBoundRestriction.kt

 package rocks.theodolite.core.strategies.restrictionstrategy
 
 import rocks.theodolite.core.Results
+import java.util.*
 
 /**
  * The [LowerBoundRestriction] sets the lower bound of the resources to be examined in the experiment to the value
@@ -13,7 +14,8 @@ import rocks.theodolite.core.Results
 class LowerBoundRestriction(results: Results) : RestrictionStrategy(results) {
 
     override fun apply(xValue: Int, yValues: List<Int>): List<Int> {
-        val maxXValue = this.results.getMaxBenchmarkedXDimensionValue(xValue)
+        // Get previous largest x value or return full list
+        val maxXValue = this.results.getMaxBenchmarkedXDimensionValue(xValue) ?: return yValues.toList()
         // Get previous largest y value or restrict to empty list
         val lowerBound: Int = this.results.getOptYDimensionValue(maxXValue) ?: return listOf()
         return yValues.filter { x -> x >= lowerBound }