def resolve_parameters(req, headers, param_map):
# substitute variables based on parameter mapping
req.url = Template(req.url).substitute(param_map)
req.body = Template(req.body).substitute(param_map)
for header in headers:
splat = Template(header).substitute(param_map).split(':', 1)
header = splat.pop(0).strip()
req.add_header(header, ''.join(splat).strip())
return req
