class_docstr: Fixed-size NumPy array ring buffer
docstr: Return buffer stripped to size of actual data
code: def get_buffer(self):
      """Return buffer stripped to size of actual data"""
      if self.history_size < self.max_history_size:
          return self.buffer[-self.history_size :]
      else:
          return self.buffer
  
imports: import time, sys, os
  from Qt import QtCore
  import numpy
  from qspectrumanalyzer.utils import smooth
  from qspectrumanalyzer.backends import soapy_power
label_desc: Use image node_id 3 for calling the HistoryBuffer obj's underlying member method code with example usage: obj.get_buffer() and returns: self, self