Returns the state, action and observation variables as a dictionary
        in the case of table type parameter and a nested structure in case of
        decision diagram parameter

        Examples
        --------
        >>> reader = PomdpXReader('Test_PomdpX.xml')
        >>> reader.get_initial_beliefs()
        [{'Var': 'rover_0',
          'Parent': ['null'],
          'Type': 'TBL',
          'Parameter': [{'Instance': ['-'],
          'ProbTable': ['0.0', '1.0', '0.0']}]
         },
         {'Var': '',
          '...': ...,'
          '...': '...',
          }]

def get_initial_beliefs(self):
        """
        Returns the state, action and observation variables as a dictionary
        in the case of table type parameter and a nested structure in case of
        decision diagram parameter

        Examples
        --------
        >>> reader = PomdpXReader('Test_PomdpX.xml')
        >>> reader.get_initial_beliefs()
        [{'Var': 'rover_0',
          'Parent': ['null'],
          'Type': 'TBL',
          'Parameter': [{'Instance': ['-'],
          'ProbTable': ['0.0', '1.0', '0.0']}]
         },
         {'Var': '',
          '...': ...,'
          '...': '...',
          }]
        """
        initial_state_belief = []
        for variable in self.network.findall('InitialStateBelief'):
            for var in variable.findall('CondProb'):
                cond_prob = defaultdict(list)
                cond_prob['Var'] = var.find('Var').text
                cond_prob['Parent'] = var.find('Parent').text.split()
                if not var.find('Parameter').get('type'):
                    cond_prob['Type'] = 'TBL'
                else:
                    cond_prob['Type'] = var.find('Parameter').get('type')
                cond_prob['Parameter'] = self.get_parameter(var)
                initial_state_belief.append(cond_prob)

        return initial_state_belief