Basemap does not respects False Easting or False Northing

While creating a basemap from an EPSG code with the x_0 or y_0 (False Easting and False Northing), the Basemap instance does not respect those values. I tried with 'tmerc' projections only because it's of my interest. I leave an example:

Suppose I want to use this EPSG basemap:

# POSGAR 94 / Argentina 1
<22181> +proj=tmerc +lat_0=-90 +lon_0=-72 +k=1 +x_0=1500000 +y_0=0 +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs  <>

It can be found in "basemap/data/epsg" file.

Then I create the basemap and print its parameters:

from mpl_toolkits.basemap import Basemap

lon_min, lat_min = -75, -45
lon_max, lat_max = -70, -40
bm = Basemap(epsg=22181,
             llcrnrlon=lon_min, llcrnrlat=lat_min,
             urcrnrlon=lon_max, urcrnrlat=lat_max)

print bm.proj4string

I get the following output:
+a=6378137.0 +b=6356752.31425 +k_0=1.0 +y_0=-5012640.49452 +lon_0=-72.0 +proj=tmerc +x_0=236540.642361 +units=m +lat_0=-90.0

As we can see, the Basemap overrides the false easting and false northing information:
+x_0=236540.642361 +y_0=-5012640.49452

It would be great that the Basemap respect those values and even better if they can be passed as arguments while initializing it in the usual way (without using EPSG codes), for example:

bm = Basemap(projection='tmerc',
             lon_0=lon_0, lat_0=lat_0,
             x_0=x_0, y_0=y_0
             llcrnrlon=lon_min, llcrnrlat=lat_min,
             urcrnrlon=lon_max, urcrnrlat=lat_max)

Inizia dal costruttore Basemap e dalla ricerca EPSG usando la voce per 22181 in basemap/data/epsg; riproduci l’esempio tmerc e verifica come i parametri di proiezione diventano proj4string. Conferma che x_0 e y_0 forniti da EPSG vengano mantenuti e determina come debbano essere gestiti gli argomenti equivalenti del costruttore. Il lavoro è completato quando l’esempio conserva entrambi gli offset falsi e la copertura di regressione li verifica.