GapiAuthSourceStores data used to authorize requests.
type oauth1_data = {signature_method : GapiCore.SignatureMethod.t;consumer_key : string;consumer_secret : string;token : string;secret : string;}type oauth1_params = {http_method : GapiCore.HttpMethod.t;url : string;post_fields_to_sign : (string * string) list;}type oauth2_data = {client_id : string;client_secret : string;oauth2_token : string;refresh_token : string;refresh_access_token : (unit -> string) option;}type oauth2_service_account_data = {service_account_credentials_json : string;scopes : string list;user_to_impersonate : string option;oauth2_service_account_token : string;refresh_service_account_access_token : (unit -> string) option;}type authentication = | NoAuth| ClientLogin of string| OAuth1 of oauth1_data| OAuth2 of oauth2_data| OAuth2ServiceAccount of oauth2_service_account_dataval generate_authorization_header :
?oauth1_params:oauth1_params ->
authentication ->
string option