def normalize(returns, starting_value=<NUM_LIT:1>):
return starting_value * (returns / returns.iloc[<NUM_LIT:0>])<EOL>
Normalizes a returns timeseries based on the first value.

Parameters
----------
returns : pd.Series
    Daily returns of the strategy, noncumulative.
     - See full explanation in tears.create_full_tear_sheet.
starting_value : float, optional
   The starting returns (default 1).

Returns
-------
pd.Series
    Normalized returns.