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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 _is_span_inside(self, span, covered_spans):
 """Returns True if `span` falls within `covered_spans`. :param span: start and end indices of a span :type span: 2-`tuple` of `int` :param covered_spans: list of start and end indices for parts of the text already covered by a sequence :type covered_spans: `list` of 2-`tuple` of `int` :rtype: `bool` """

        start = span[0]
        end = span[1]
        for c_start, c_end in covered_spans:
            if start >= c_start and end <= c_end:
                return True
        return False