code: def calc_leverage(exposure, net_liq):
      if net_liq != 0:
          return exposure / net_liq
  
      return np.inf
  
imports: from __future__ import division
  import logbook
  import numpy
  from collections import namedtuple
  from catalyst.assets import Future
  from six import itervalues, iteritems
  import catalyst.protocol
  from catalyst.constants import LOG_LEVEL
label_desc: Use image node_id 2 for calling a global function with example usage: calc_leverage(exposure, net_liq) and returns: np, unknown