Create a new security group for your account.
        This will create the security group within the region you
        are currently connected to.

        :type name: string
        :param name: The name of the new security group

        :type description: string
        :param description: The description of the new security group

        :type vpc_id: string
        :param vpc_id: The ID of the VPC to create the security group in,
                       if any.

        :rtype: :class:`boto.ec2.securitygroup.SecurityGroup`
        :return: The newly created :class:`boto.ec2.keypair.KeyPair`.

def create_security_group(self, name, description, vpc_id=None):
        """
        Create a new security group for your account.
        This will create the security group within the region you
        are currently connected to.

        :type name: string
        :param name: The name of the new security group

        :type description: string
        :param description: The description of the new security group

        :type vpc_id: string
        :param vpc_id: The ID of the VPC to create the security group in,
                       if any.

        :rtype: :class:`boto.ec2.securitygroup.SecurityGroup`
        :return: The newly created :class:`boto.ec2.keypair.KeyPair`.
        """
        params = {
            'GroupName': name,
            'GroupDescription': description
        }

        if vpc_id is not None:
            params['VpcId'] = vpc_id

        group = self.get_object('CreateSecurityGroup', params,
                                SecurityGroup, verb='POST')
        group.name = name
        group.description = description
        return group