class_docstr: Abstract base class for time stretching
  
  This contains the deformation functions and
  annotation query mapping, but does not manage
  state or parameters.
code: def __init__(self):
      BaseTransformer.__init__(self)
  
      # Build the annotation mappers
      self._register(".*", self.deform_times)
      self._register("tempo", self.deform_tempo)
  
imports: import pyrubberband
  import numpy
  from ..base import BaseTransformer, _get_rng
label_desc: Use image node_id 1 to create a new AbstractTimeStretch object from inherited base classes: BaseTransformer with example: obj = AbstractTimeStretch()