How to update projection of layers in Geoserver using gsconfig

Im using following code to find projection of layer

from geoserver.catalog import Catalog 
cat=Catalog("http:// localhost:8080/geoserver/rest") 
myResource = cat.get_resources(store='storeName', workspace='workspaceName')
layers = cat.get_layers(myResource)
for layer in layers:
    layer.projection

I found that few layers are having projection "None". How can I update those layers projection with "EPSG:4326" using gs config.