Change contravariant tensor to covariant tensor in einsteinpy package

Using einsteinpy package of Python, I am defining the electromagnetic tensor (or any other arbitrary tensor). While defining, I am defining it as 'uu' tensor using the BaseRelativityTensor class file. I want the 'll' version from this, ie. F_covariant from F_contravariant. But the package seems not to provide any .change_config() property, which EinsteinTensor (another class which defines (G^{\mu\nu})) does.

FYI: I am using the 0.3.1 version of the package.

So my question is, once F^{\mu\nu} has been defined as a BaseRelativityTensor, how to get (F_{\mu\nu}) from F^{\mu\nu}? My code is given below:

from IPython.display import display
import sympy as sp
from einsteinpy.symbolic import BaseRelativityTensor, MetricTensor

Ex, Ey, Ez, Bx, By, Bz, c = sp.symbols("E_x E_y E_z B_x B_y B_z c")
t, x, y, z = sp.symbols("t x y z")

# Define Minkowski metric (signature -,+,+,+)
eta = sp.Array([
    [-1, 0, 0, 0],
    [ 0, 1, 0, 0],
    [ 0, 0, 1, 0],
    [ 0, 0, 0, 1]
])
syms = (t, x, y, z)
metric = MetricTensor(eta, syms)
g = metric.tensor()

# Define the F array for F^{mu,nu}
F_contra_array = sp.Array([
    [0,    Ex/c,   Ey/c,   Ez/c],
    [-Ex/c, 0,     Bz,    -By],
    [-Ey/c, -Bz,   0,      Bx],
    [-Ez/c, By,   -Bx,     0]
])

# Define contravariant tensor F^{mu nu}
F_contra = BaseRelativityTensor(F_contra_array, syms, "uu", 
                            parent_metric=metric)
print("F^{mu nu} =")
display(F_contra.tensor())