<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_filter_gain(b, a, f_gain, fs):
 """ Given filter coefficients, return the gain at a particular frequency. Parameters b : list List of linear filter b coefficients a : list List of linear filter a coefficients f_gain : int or float, optional The frequency at which to calculate the gain fs : int or float, optional The sampling frequency of the system """

    # Save the passband gain
    w, h = signal.freqz(b, a)
    w_gain = f_gain * 2 * np.pi / fs

    ind = np.where(w >= w_gain)[0][0]
    gain = abs(h[ind])

    return gain