  A spacetime endowed with an anisotropic fluid is proposed for the interior of
a Schwarzschild black hole. The geometry has an instantaneous Minkowski form
and is a solution of Einstein's equations with a stress tensor on the r.h.s.
obeying all the energy conditions.
  The interior fluid is compressible, with time dependent shear and bulk
viscosity coefficients. The energy density $\rho$ and the ''radial'' pressure
$p$ observe the equation of state $p + \rho = 0$ (as for dark energy), with no
pressures on $\theta-$ and $\phi-$ directions. However, the angular components
of the viscous part of the stress tensor are nonvanishing and equals the energy
density of the fluid.
