Calculate the signature for the given secret and arguments.

def fost_hmac_request_signature(
    secret, method, path, timestamp, headers = {}, body = ''):
    """
        Calculate the signature for the given secret and arguments.
    """
    signed_headers, header_values = 'X-FOST-Headers', []
    for header, value in headers.items():
        signed_headers += ' ' + header
        header_values.append(value)
    return fost_hmac_request_signature_with_headers(
        secret, method, path, timestamp,
        [signed_headers] + header_values, body)