class_docstr: An FXRateReader backed by HDF5.
  
  Parameters
  ----------
  group : h5py.Group
      Top-level group written by an :class:`HDF5FXRateWriter`.
  default_rate : str
      Rate to use when ``get_rates`` is called requesting the default rate.
code: def __init__(self, group, default_rate):
      self._group = group
      self._default_rate = default_rate
  
      if self.version != HDF5_FX_VERSION:
          raise ValueError(
              "FX Reader version ({}) != File Version ({})".format(
                  HDF5_FX_VERSION,
                  self.version,
              )
          )
  
imports: from interface import implements
  import h5py
  from logbook import Logger
  import numpy
  import pandas
  from zipline.utils.memoize import lazyval
  from zipline.utils.numpy_utils import bytes_array_to_native_str_object_array
  from .base import FXRateReader, DEFAULT_FX_RATE
  from .utils import check_dts, is_sorted_ascending
label_desc: Use image node_id 1 to create a new HDF5FXRateReader object from inherited base classes:  with example: obj = HDF5FXRateReader(group, default_rate)