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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 addLabel(self, aminoAcidLabels, excludingModifications=None):
 """Adds a new labelstate. :param aminoAcidsLabels: Describes which amino acids can bear which labels. Possible keys are the amino acids in one letter code and 'nTerm', 'cTerm'. Possible values are the modifications ids from :attr:`maspy.constants.aaModMass` as strings or a list of strings. An example for one expected label at the n-terminus and two expected labels at each Lysine: ``{'nTerm': 'u:188', 'K': ['u:188', 'u:188']}`` :param excludingModifications: optional, A Dectionary that describes which modifications can prevent the addition of labels. Keys and values have to be the modifications ids from :attr:`maspy.constants.aaModMass`. The key specifies the modification that prevents the label modification specified by the value. For example for each modification 'u:1' that is present at an amino acid or terminus of a peptide the number of expected labels at this position is reduced by one: ``{'u:1':'u:188'}`` """

        if excludingModifications is not None:
            self.excludingModifictions = True

        labelEntry = {'aminoAcidLabels': aminoAcidLabels,
                      'excludingModifications': excludingModifications
                      }
        self.labels[self._labelCounter] = labelEntry
        self._labelCounter += 1