docs: def fiGroupFromLinkageGroup(matchArr, arrPos, groupId, timeKey, massKey):
      """ #TODO: docstring
      """
      fgi = Fgi(groupId)
      matchArr['isAnnotated'][arrPos]
  
      minT = numpy.min(matchArr[timeKey][arrPos])
      maxT = numpy.max(matchArr[timeKey][arrPos])
      minM = numpy.min(matchArr[massKey][arrPos])
      maxM = numpy.max(matchArr[massKey][arrPos])
  
      fgi.isValid = True
      fgi.specfiles = matchArr['specfile'][arrPos].tolist()
      fgi.featureIds = matchArr['id'][arrPos].tolist()
      fgi.isAnnotated = numpy.any(matchArr['isAnnotated'][arrPos])
      fgi.coordinates = ((minT, maxT), (minM, maxM))
      #fgi.clusterType = clusterType
  
      return fgi