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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _regressor_names(con_name, hrf_model, fir_delays=None):
 """ Returns a list of regressor names, computed from con-name and hrf type Parameters con_name: string identifier of the condition hrf_model: string or None, hrf model chosen fir_delays: 1D array_like, optional, Delays used in case of an FIR model Returns ------- names: list of strings, regressor names """

    if hrf_model in ['glover', 'spm', None]:
        return [con_name]
    elif hrf_model in ["glover + derivative", 'spm + derivative']:
        return [con_name, con_name + "_derivative"]
    elif hrf_model in ['spm + derivative + dispersion',
                       'glover + derivative + dispersion']:
        return [con_name, con_name + "_derivative", con_name + "_dispersion"]
    elif hrf_model == 'fir':
        return [con_name + "_delay_%d" % i for i in fir_delays]