What is the burden on a proponent of a settlement?

"The burden is on the proponent of the settlement to show that it is fair and reasonable. [Citation.] However, there is a presumption of fairness when (1) the settlement is reached through arm's-length bargaining; (2) investigation and discovery are sufficient to allow counsel and the trial court to act intelligently; (3) counsel is experienced in similar litigation; and (4) the percentage of objectors is small." (Reed v. United Teachers Los Angeles (2012) 208 Cal.App.4th 322, 336-337.)