Transfer attributes to :class:`Sii` elements from the corresponding
        :class`Si` in :class:`MsrunContainer.sic <MsrunContainer>`. If an
        attribute is not present in the ``Si`` the attribute value in the
        ``Sii``is set to ``None``.

        Attribute examples: 'obsMz', 'rt', 'charge', 'tic', 'iit', 'ms1Id'

        :param msrunContainer: an instance of :class:`MsrunContainer` which has
            imported the corresponding specfiles
        :param specfiles: the name of an ms-run file or a list of names. If None
            all specfiles are selected.
        :param attributes: a list of ``Si`` attributes that should be
            transfered.

def addSiInfo(self, msrunContainer, specfiles=None,
                  attributes=['obsMz', 'rt', 'charge']):
        """Transfer attributes to :class:`Sii` elements from the corresponding
        :class`Si` in :class:`MsrunContainer.sic <MsrunContainer>`. If an
        attribute is not present in the ``Si`` the attribute value in the
        ``Sii``is set to ``None``.

        Attribute examples: 'obsMz', 'rt', 'charge', 'tic', 'iit', 'ms1Id'

        :param msrunContainer: an instance of :class:`MsrunContainer` which has
            imported the corresponding specfiles
        :param specfiles: the name of an ms-run file or a list of names. If None
            all specfiles are selected.
        :param attributes: a list of ``Si`` attributes that should be
            transfered.
        """
        if specfiles is None:
            specfiles = [_ for _ in viewkeys(self.info)]
        else:
            specfiles = aux.toList(specfiles)

        for specfile in specfiles:
            if specfile not in self.info:
                warntext = 'Error while calling "SiiContainer.addSiInfo()": '\
                           '"%s" is not present in "SiiContainer.info"!'\
                            % (specfile, )
                warnings.warn(warntext)
            elif specfile not in msrunContainer.info:
                warntext = 'Error while calling "SiiContainer.addSiInfo()": '\
                           '"%s" is not present in "MsrunContainer.info"'\
                            % (specfile, )
                warnings.warn(warntext)
            else:
                for identifier in self.container[specfile]:
                    si = msrunContainer.sic[specfile][identifier]
                    for sii in self.container[specfile][identifier]:
                        for attribute in attributes:
                            setattr(sii, attribute,
                                    getattr(si, attribute, None)
                                    )