What is the test for determining whether restraints used by the police during an interview constitute a formal arrest?

"Custody determinations are resolved by an objective standard: Would a reasonable person interpret the restraints used by the police as tantamount to a formal arrest? [Citations.] The totality of the circumstances surrounding an incident must be considered as a whole. [Citation.] Although no one factor is controlling, the following circumstances should be considered: `(1) [W]hether the suspect has been formally arrested; (2) absent formal arrest, the length of the detention; (3) the location; (4) the ratio of officers to suspects; and (5) the demeanor of the officer, including the nature of the questioning.' [Citation.] Additional factors are whether the suspect agreed to the interview and was informed he or she could terminate the questioning, whether police informed the person he or she was considered a witness or suspect, whether there were restrictions on the suspect's freedom of movement during the interview, and whether police officers dominated and controlled the interrogation or were `aggressive, confrontational, and/or accusatory,' whether they pressured the suspect, and whether the suspect was arrested at the conclusion of the interview. [Citation.]" (People v. Pilster, supra, 138 Cal.App.4th at pp. 1403-1404, fn. omitted.)