Animated markers missing when using pre1970 dates in TimestampedGeoJson

Animated markers missing when using pre1970 dates in TimestampedGeoJson. I understand this functionality from Leaflet.TimeDimension, but had thought this issue was fixed there (Merged pull request: https://github.com/socib/Leaflet.TimeDimension/pull/91).

Please add a code sample or a nbviewer link, copy-pastable if possible

import folium
from folium.plugins import TimestampedGeoJson

# Post-1970 timestamps: 1970-01-02, 1970-01-03, 1970-01-04
milliseconds_per_day = 1000 * 60 * 60 * 24
post_1970_timestamps=[1*milliseconds_per_day, 2*milliseconds_per_day, 3*milliseconds_per_day]
# Pre-1970 timestamps: 1969-12-29, 1969-12-30, 1969-12-31
pre_1970_timestamps=[0-time for time in post_1970_timestamps]
# Ensure pre_1970_timestamps are in ascending order:
pre_1970_timestamps.reverse()

m = folium.Map(location=[0,0],zoom_start=2)
ts=TimestampedGeoJson({
     'type': 'FeatureCollection',
     'features': [
       {
         'type': 'Feature',
         'geometry': {
           'type': 'LineString',
           'coordinates': [[-70,-25],[-70,35],[70,35]],
           },
         'properties': {
            # Dates shown in time slider controls, but no markers displayed on map
            # Contrast behaviour when times read from post_1970_timestamps list:
            # - animated markers shown on map as per example
            'times': pre_1970_timestamps
            #'times': post_1970_timestamps 
           }
         }
       ]
     })
ts.add_to(m)
m

Problem description

No markers shown on maps using TimestampedGeoJson with dates pre 1970 (as held in pre_1970_timestamps list)

Expected Output

Animated markers as per the TimestampedGeoJson with post_1970_timestamps

Output of folium.__version__

0.10.0

Beginnen Sie beim Einstiegspunkt folium.plugins.TimestampedGeoJson und vergleichen Sie die generierte Leaflet.TimeDimension-Konfiguration für negative Zeitstempel mit dem bereitgestellten Beispiel nach 1970. Reproduzieren Sie das Beispiel, verfolgen Sie nach, wie die Werte vor 1970 die Animation erreichen, und überprüfen Sie, dass animierte Marker für beide Zeitstempelbereiche erscheinen.