code: def _zseries_int(zs):
      """Integrate a z-series.
  
      The integral is with respect to x, not z. This is achieved by a change
      of variable using dx/dz given in the module notes.
  
      Parameters
      ----------
      zs : z-series
          The z-series to integrate
  
      Returns
      -------
      integral : z-series
          The indefinite integral
  
      Notes
      -----
      The zseries for x (ns) has been multiplied by two in order to avoid
      using floats that are incompatible with Decimal and likely other
      specialized scalar types. This scaling has been compensated by
      dividing the resulting zs by two.
  
      """
      n = 1 + len(zs) // 2
      ns = np.array([-1, 0, 1], dtype=zs.dtype)
      zs = _zseries_mul(zs, ns)
      div = np.arange(-n, n + 1) * 2
      zs[:n] /= div[:n]
      zs[n + 1 :] /= div[n + 1 :]
      zs[n] = 0
      return zs
  
imports: import numpy
  import numpy.linalg
  from numpy.core.multiarray import normalize_axis_index
  from .None import polyutils
  from ._polybase import ABCPolyBase
label_desc: Use image node_id 6 for calling a global function with example usage: _zseries_int(zs) and returns: zs