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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 get_lower_triangle_correlation_matrix(self, sites, imt):
 """ Get lower-triangle matrix as a result of Cholesky-decomposition of correlation matrix. The resulting matrix should have zeros on values above the main diagonal. The actual implementations of :class:`BaseCorrelationModel` interface might calculate the matrix considering site collection and IMT (like :class:`JB2009CorrelationModel` does) or might have it pre-constructed for a specific site collection and IMT, in which case they will need to make sure that parameters to this function match parameters that were used to pre-calculate decomposed correlation matrix. :param sites: :class:`~openquake.hazardlib.site.SiteCollection` to create correlation matrix for. :param imt: Intensity measure type object, see :mod:`openquake.hazardlib.imt`. """

        return numpy.linalg.cholesky(self._get_correlation_matrix(sites, imt))