def _setup_linear_propagator(self, struct):
"""Sets up the noise-independent, linear propagator
Returns:
The propagator as CSR Matrix
"""
i, j, a = hcons.setup_linear_propagator(struct.vecind,
struct.indab,
struct.indbl,
self._h_sys,
self._g,
self._gamma + 1.j*self._omega,
self._l_map,
self._with_terminator)
csr = CSRMatrix((a, j, i))
csr.sum_duplicates()
csr.eliminate_zeros()
return csr
