class_docstr: Class to wrap MINC1 format opened netcdf object
  
  Although it has some of the same methods as a ``Header``, we use
  this only when reading a MINC file, to pull out useful header
  information, and for the method of reading the data out
docstr: Get real-world sizes of voxels
docstr_tok: ["Get","real-world","sizes","of","voxels"]
code: def get_zooms(self):
      """Get real-world sizes of voxels"""
      # zooms must be positive; but steps in MINC can be negative
      return tuple(
          abs(float(dim.step)) if hasattr(dim, "step") else 1.0
          for dim in self._dims
      )
  
imports: from __future__ import annotations
  from numbers import Integral
  import numpy
  from .externals.netcdf import netcdf_file
  from .fileslice import canonical_slicers
  from .spatialimages import SpatialHeader, SpatialImage
label_desc: Use image node_id 5 for calling the Minc1File obj's underlying member method code with example usage: obj.get_zooms() and returns: tuple