(object val):     """     Return boolean describing of the input is NA-like, defined here as any     of:      - None      - nan      - NaT      - np.datetime00 representation of NaT      - np.timedelta00 representation of NaT      - NA      Parameters     ----------     val : object      Returns     -------     bool      Notes     -----     The difference between `checknull` and `checknull_old` is that `checknull`     does *not* consider INF or NEGINF to be NA.     """     