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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _GetAFF4AttributeForReportType(report_type ):
 """Returns the corresponding AFF4 attribute for the given report type."""

  if report_type == rdf_stats.ClientGraphSeries.ReportType.GRR_VERSION:
    return aff4_stats.ClientFleetStats.SchemaCls.GRRVERSION_HISTOGRAM
  elif report_type == rdf_stats.ClientGraphSeries.ReportType.OS_TYPE:
    return aff4_stats.ClientFleetStats.SchemaCls.OS_HISTOGRAM
  elif report_type == rdf_stats.ClientGraphSeries.ReportType.OS_RELEASE:
    return aff4_stats.ClientFleetStats.SchemaCls.RELEASE_HISTOGRAM
  elif report_type == rdf_stats.ClientGraphSeries.ReportType.N_DAY_ACTIVE:
    return aff4_stats.ClientFleetStats.SchemaCls.LAST_CONTACTED_HISTOGRAM
  else:
    raise ValueError("Unknown report type %s." % report_type)