plot_real_imag(
    sqrt(x), (x, -3, 3), real=False, imag=False, abs=True, arg=True)
# Expected:
## Plot object containing:
## [0]: cartesian line: abs(sqrt(x)) for x over (-3.0, 3.0)
## [1]: cartesian line: arg(sqrt(x)) for x over (-3.0, 3.0)