code: def make_tree(self):
          
          self.tree['is_ready'] = False
          leaf_count = len(self.tree['leaves'])
          if leaf_count > 0:
              # skip this whole process if there are no leaves added to the tree
              self._unshift(self.tree['levels'], self.tree['leaves'])
              while len(self.tree['levels'][0]) > 1:
                  self._unshift(self.tree['levels'], self._calculate_next_level())
          self.tree['is_ready'] = True
docs: Generates the merkle tree.