cards: remove empty erase() methods.

Some of the cards do not implement the erase method that each card
should have. However, having an empty method in each of those classes
does not make too much sense. Lets rather have an erase method in the
superclass (Card) that prints a warning to inform the user that erasing
the spcified card is not supported.

Change-Id: If5add960ec0cab58a01d8f83e6af8cb86ec70a8d

pySim/cards.py

@@ -37,6 +37,10 @@ class Card(object):
 	def reset(self):
 		self._scc.reset_card()
 
+	def erase(self):
+		print("warning: erasing is not supported for specified card type!")
+		return
+
 	def verify_adm(self, key):
 		'''
 		Authenticate with ADM key
@@ -529,8 +533,6 @@ class GrcardSim(Card):
 
 		# FIXME: EF.MSISDN
 
-	def erase(self):
-		return
 
 class SysmoSIMgr1(GrcardSim):
 	"""
@@ -575,9 +577,6 @@ class SysmoUSIMgr1(Card):
 			)
 		data, sw = self._scc._tp.send_apdu_checksw("0099000033" + par)
 
-	def erase(self):
-		return
-
 
 class SysmoSIMgr2(Card):
 	"""
@@ -653,8 +652,6 @@ class SysmoSIMgr2(Card):
 		if p.get('smsp'):
 			data, sw = self._scc.update_record('6f42', 1, lpad(p['smsp'], 80))
 
-	def erase(self):
-		return
 
 class SysmoUSIMSJS1(Card):
 	"""
@@ -759,9 +756,6 @@ class SysmoUSIMSJS1(Card):
 			r = self._scc.select_file(['3f00', '7f10'])
 			data, sw = self._scc.update_record('6F40', 1, data, force_len=True)
 
-	def erase(self):
-		return
-
 
 class FairwavesSIM(Card):
 	"""
@@ -903,10 +897,6 @@ class FairwavesSIM(Card):
 			if sw != '9000':
 				print("Programming ACC failed with code %s"%sw)
 
-	def erase(self):
-		return
-
-
 class OpenCellsSim(Card):
 	"""
 	OpenCellsSim
@@ -1046,9 +1036,6 @@ class WavemobileSim(Card):
 
 		return None
 
-	def erase(self):
-		return
-
 
 class SysmoISIMSJA2(Card):
 	"""
@@ -1169,9 +1156,6 @@ class SysmoISIMSJA2(Card):
 
 		return
 
-	def erase(self):
-		return
-
 
 # In order for autodetection ...
 _cards_classes = [ FakeMagicSim, SuperSim, MagicSim, GrcardSim,