Module for basemaps. Each basemap is defined as item in the ee_basemaps dictionary. For example, to access Google basemaps, use the following:
ee_basemaps['ROADMAP'], ee_basemaps['SATELLITE'], ee_basemaps['HYBRID'].
More WMS basemaps can be found at the following websites:
USGS National Map: https://viewer.nationalmap.gov/services/
MRLC NLCD Land Cover data: https://viewer.nationalmap.gov/services/
FWS NWI Wetlands data: https://www.fws.gov/wetlands/Data/Web-Map-Services.html