code: def _get_frame_offset(self, frame=0):
      return int(self._mlist[frame][1] * BLOCK_SIZE)
  
imports: import warnings
  from numbers import Integral
  import numpy
  from .arraywriters import make_array_writer
  from .fileslice import canonical_slicers, predict_shape, slice2outax
  from .spatialimages import SpatialHeader, SpatialImage
  from .volumeutils import array_from_file, make_dt_codes, native_code, swapped_code
  from .wrapstruct import WrapStruct
label_desc: Use image node_id 8 for calling the EcatSubHeader obj's underlying member method code with example usage: obj._get_frame_offset(frame) and returns: int