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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 CheckClientApprovalRequest(approval_request):
 """Checks if a client approval request is granted."""


  _CheckExpired(approval_request)
  _CheckHasEnoughGrants(approval_request)

  if not client_approval_auth.CLIENT_APPROVAL_AUTH_MGR.IsActive():
    return True

  token = access_control.ACLToken(username=approval_request.requestor_username)
  approvers = set(g.grantor_username for g in approval_request.grants)

  labels = sorted(
      data_store.REL_DB.ReadClientLabels(approval_request.subject_id),
      key=lambda l: l.name)
  for label in labels:
    client_approval_auth.CLIENT_APPROVAL_AUTH_MGR.CheckApproversForLabel(
        token, rdfvalue.RDFURN(approval_request.subject_id),
        approval_request.requestor_username, approvers, label.name)

  return True