r-cycle basis.
    This class has three built-in policies, as put forth in the paper.
    &#34;triangular&#34;:
        A basic triangular cycle w/ no amplitude scaling.
    &#34;triangular2&#34;:
        A basic triangular cycle that scales initial amplitude by half each cycle.
    &#34;exp_range&#34;:
        A cycle that scales initial amplitude by gamma**(cycle iterations) at each
        cycle iteration.
    For more detail, please see paper.

    # Example
        ```python
            clr = CyclicLR(