class_docstr: Multiple proximal operator. This allows to apply sequentially a list
  of proximal operators. This is convenient when one wants to apply different
  proximal operators on different parts of a vector.
  
  Parameters
  ----------
  proxs : `tuple` of `Prox`
      A tuple of prox operators to be applied successively.
  
  Attributes
  ----------
  dtype : `{'float64', 'float32'}`
      Type of the arrays used.
code: def _call(self, coeffs: np.ndarray, step: object, out: np.ndarray):
      self._prox.call(coeffs, step, out)
  
file_path: tick/tick/prox/prox_multi.py
imports: import numpy
  from .base import Prox
  from .build.prox import ProxMultiDouble
  from .build.prox import ProxMultiFloat
  from tick.prox import ProxZero
label_desc: Use image node_id 2 for calling the ProxMulti obj's underlying member method code with example usage: obj._call(coeffs, step, out) without return types