class_docstr: Fixed-size NumPy array ring buffer
code: def __init__(self, data_size, max_history_size, dtype=float):
      self.data_size = data_size
      self.max_history_size = max_history_size
      self.history_size = 0
      self.counter = 0
      self.buffer = np.empty(
          shape=(max_history_size, data_size), dtype=dtype
      )
  
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 1 to create a new HistoryBuffer object  with example: obj = HistoryBuffer(data_size, max_history_size, dtype)