simplify molecule data class.

Author: francastagna

core/src/main/kotlin/org/evomaster/core/search/algorithms/CroAlgorithm.kt

@@ -5,12 +5,6 @@ import org.evomaster.core.search.Individual
 import org.evomaster.core.search.algorithms.wts.WtsEvalIndividual
 import kotlin.math.abs
 
-data class Molecule<T : Individual>(
-    var suite: WtsEvalIndividual<T>,
-    var kineticEnergy: Double,
-    var numCollisions: Int
-)
-
 /**
  * Chemical Reaction Optimization (CRO)
  *
@@ -24,6 +18,12 @@ class CroAlgorithm<T> : AbstractGeneticAlgorithm<T>() where T : Individual {
 
     private data class EnergyContext(var container: Double)
 
+    data class Molecule<T : Individual>(
+        var suite: WtsEvalIndividual<T>,
+        var kineticEnergy: Double,
+        var numCollisions: Int
+    )
+
     private val molecules: MutableList<Molecule<T>> = mutableListOf()
 
     // container is the global energy reservoir.