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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 modAminoacidsFromLabelInfo(labelDescriptor):
 """Returns a set of all amino acids and termini which can bear a label, as described in "labelDescriptor". :param labelDescriptor: :class:`LabelDescriptor` describes the label setup of an experiment :returns: #TODO: docstring """

    modAminoacids = set()
    for labelStateEntry in viewvalues(labelDescriptor.labels):
        for labelPositionEntry in viewkeys(labelStateEntry['aminoAcidLabels']):
            for modAminoacid in aux.toList(labelPositionEntry):
                if modAminoacid != '':
                    modAminoacids.add(modAminoacid)
    return modAminoacids