moved __len__ method from array to potential, following moving size() method

Author: MauroCE

brml/array.py

@@ -1,6 +1,5 @@
 import copy
 import numpy as np
-from brml.utilities import isvector
 from brml.potential import Potential
 
 
@@ -16,15 +15,6 @@ def __init__(self, variables=np.array([]), table=np.array([])):
         # Instantiate Potential class.
         super().__init__(variables, table)
 
-    def __len__(self):
-        """
-        Overwrites the behavior of the __len__ call (for instance len(Array).
-        When calling len(Array) it is equivalent to just call Array.size()
-        :return: Number of states in the Array's table
-        :rtype: numpy.array
-        """
-        return self.size()
-
     def to_logarray(self):
         """
         This function converts Array to a LogArray. At the moment the LogArray

brml/potential.py

@@ -53,6 +53,15 @@ def __repr__(self) -> str:
                                 self.variables, self.table)
         return s
 
+    def __len__(self):
+        """
+        Overwrites the behavior of the __len__ call (for instance len(Array).
+        When calling len(Array) it is equivalent to just call Array.size()
+        :return: Number of states in the Array's table
+        :rtype: numpy.array
+        """
+        return self.size()
+
     @staticmethod
     def _check_variables(variables):
         """