pub fn new<A, B, C>(web_identity_token: A, role_arn: B, role_session_name: Option<C>) -> Self
    where
        A: Into<Variable<Secret, CredentialsError>>,
        B: Into<Variable<String, CredentialsError>>,
        C: Into<Variable<Option<String>, CredentialsError>>,
    {
        Self {
            web_identity_token: web_identity_token.into(),
            role_arn: role_arn.into(),
            role_session_name: role_session_name.map(|v| v.into()),
            duration_seconds: None,
            policy: None,
            policy_arns: None
        }
    }
Create new WebIdentityProvider by explicitly passing its configuration.
rusoto/services/sts/src/custom/web_identity.rs