docs: def get_value(self, attribute, section, default=""):
          """
          Returns requested attribute value.
  
          Usage::
  
              >>> content = ["[Section A]\\n", "; Comment.\\n", "Attribute 1 = \\"Value A\\"\\n", "\\n", \
  "[Section B]\\n", "Attribute 2 = \\"Value B\\"\\n"]
              >>> sections_file_parser = SectionsFileParser()
              >>> sections_file_parser.content = content
              >>> sections_file_parser.parse()
              <foundations.parsers.SectionsFileParser object at 0x679302423>
              >>> sections_file_parser.get_value("Attribute 1", "Section A")
              u'Value A'
  
          :param attribute: Attribute name.
          :type attribute: unicode
          :param section: Section containing the searched attribute.
          :type section: unicode
          :param default: Default return value.
          :type default: object
          :return: Attribute value.
          :rtype: unicode
          """
  
          if not self.attribute_exists(attribute, section):
              return default
  
          if attribute in self.__sections[section]:
              value = self.__sections[section][attribute]
          elif foundations.namespace.set_namespace(section, attribute) in self.__sections[section]:
              value = self.__sections[section][foundations.namespace.set_namespace(section, attribute)]
          LOGGER.debug("> Attribute: '{0}', value: '{1}'.".format(attribute, value))
          return value