code: def make_tuple(arr):
      """Make a list of index tuples from array
  
      Parameters
      ----------
      arr : array
  
      Returns
      -------
      out : list
  
      Examples
      --------
      >>> import numpy as np
      >>> from mlens.index.base import make_tuple
      >>> _make_tuple(np.array([0, 1, 2, 5, 6, 8, 9, 10]))
      [(0, 3), (5, 7), (8, 11)]
      """
      out = list()
      t1 = t0 = arr[0]
      for i in arr[1:]:
          if i - t1 <= 1:
              t1 = i
              continue
  
          out.append((t0, t1 + 1))
          t1 = t0 = i
  
      out.append((t0, t1 + 1))
      return out
  
imports: from __future__ import division
  from abc import abstractmethod
  import numpy
  from ..externals.sklearn.base import BaseEstimator
label_desc: Use image node_id 3 for calling a global function with example usage: make_tuple(arr) and returns: out