diff --git a/check.py b/check.py
index d2502014..8f143d26 100755
--- a/check.py
+++ b/check.py
@@ -7,6 +7,54 @@ try:
 except:
   from yaml import Loader
 
+class XAvp:
+  """ Class to simulate the xavp """
+  _data = []
+  _name = ""
+
+  def __init__(self, name, data):
+    result = re.match('\$xavp\((\w+)\)', name)
+    try:
+      self._name = result.group(1)
+    except:
+      raise Exception('not a xavp')
+    self._data = data
+
+  def get(self, str):
+    pattern_nindx = '(\[(?P<%s>\d+)\])?' % 'nindx'
+    pattern_kindx = '(\[(?P<%s>\d+|\*+)\])?' % 'kindx'
+    pattern = '\$xavp\((?P<name>\w+)%s=>(?P<key>\w+)%s\)'  % (pattern_nindx, pattern_kindx)
+    result = re.match(pattern, str)
+    if result is not None:
+      if self._name != result.group('name'):
+        raise KeyError(
+          'diferent name. name:%s != %s' % (self._name, result.group(1))
+        )
+      try:
+        nindx = int(result.group('nindx'))
+      except:
+        nindx = 0
+      if self._data[nindx].has_key(result.group('key')):
+        values = self._data[nindx][result.group('key')]
+      else:
+        raise KeyError('no %s key found' % result.group('key') )
+      nsize = len(self._data)
+      if  nsize <= nindx:
+        raise IndexError('%s has %d elements' % (self._name, nsize))
+      try:
+        kindx = int(result.group('kindx'))
+      except:
+        if ( result.group('kindx') == '*' ):
+          return values
+        kindx = 0
+      ksize = len(values)
+      if  ksize <= kindx:
+        raise IndexError('%s has %d elements' % (result.group('key'), ksize))
+      #print "name: %s nindx:%d key: %s kindx: %d" % (result.group('name'), nindx, result.group('key'), kindx)
+      return values[kindx]
+    else:
+      raise KeyError('no key found')
+
 class Test:
   """ Class to create TAP output """
   _step = []
diff --git a/test_check.py b/test_check.py
new file mode 100644
index 00000000..9cc1f6f1
--- /dev/null
+++ b/test_check.py
@@ -0,0 +1,46 @@
+#!/usr/bin/env python
+from check import XAvp
+import unittest
+
+class TestXAvp(unittest.TestCase):
+
+  def setUp(self):
+    self.name = 'test'
+    self.data = [
+      {'koko': [1]},
+      {'koko': [1, 2]},
+      {'lolo': [3], 'lola': [7]},
+    ]
+    self.xavp = XAvp('$xavp(%s)' % self.name, self.data)
+
+  def test_init(self):
+    self.assertEqual(self.name, self.xavp._name)
+    self.assertItemsEqual(self.data, self.xavp._data)
+
+  def test_init_wrong_type(self):
+    self.assertRaises(Exception, self.xavp, '$var(whatever)', None)
+
+  def test_get_wrong_name(self):
+    self.assertRaises(KeyError, self.xavp.get, '$xavp(otro)')
+    self.assertRaises(KeyError, self.xavp.get, '$xavp(otro[0])')
+    self.assertRaises(KeyError, self.xavp.get, '$xavp(otro=>whatever)')
+    self.assertRaises(KeyError, self.xavp.get, '$xavp(otro[0]=>whatever)')
+
+  def test_get_wrong_nindx(self):
+    self.assertRaises(IndexError, self.xavp.get, '$xavp(test[10]=>koko)')
+    self.assertRaises(IndexError, self.xavp.get, '$xavp(test[10]=>koko[1])')
+
+  def test_get_wrong_kindx(self):
+    self.assertRaises(IndexError, self.xavp.get, '$xavp(test[0]=>koko[1])')
+    self.assertRaises(IndexError, self.xavp.get, '$xavp(test[1]=>koko[10])')
+
+  def test_get_value(self):
+    self.assertEqual(self.xavp.get('$xavp(test=>koko)'), 1)
+    self.assertEqual(self.xavp.get('$xavp(test[1]=>koko[1])'), 2)
+    self.assertEqual(self.xavp.get('$xavp(test[2]=>lola[0])'), 7)
+
+  def test_get_value_all(self):
+    self.assertItemsEqual(self.xavp.get('$xavp(test[1]=>koko[*])'), [1,2])
+
+if __name__ == '__main__':
+    unittest.main()
\ No newline at end of file