What is the test for excluding a witness from a trial?

Is there any case law where a trial judge or jury was ordered to delay or otherwise delay the trial of a witness due to the absence of the witness? ("New York", United States of America)

Does a trial judge have the authority to instruct a child as a witness that they have witnessed an assault? (MultiRegion, United States of America)

What is the test for a motion for a new trial where newly discovered evidence indicates perjury by a prosecution witness at trial? (MultiRegion, United States of America)

Is there any evidence to support a finding that a continuance of a trial would have been inconvenience to the trial of a bank witness? (MultiRegion, United States of America)

How will a court review a trial court's decision to exclude testimony from a witness? (MultiRegion, United States of America)

Is a motion for a continuance granted by the trial court on the date of trial on the basis that the trial judge abused his discretion to grant the motion? (MultiRegion, United States of America)

Does the fact that a witness testified untruthfully at a previous trial constitute a finding that he is testifying perjuriously at trial? (MultiRegion, United States of America)

Is there any case law where a trial judge abused his position in excluding or excluding the evidence? (MultiRegion, United States of America)

Does the trial judge erred in denying a post-trial motion for a new trial based upon alleged violations of sequestration order by members of the jury or marshals assigned to supervise the jury? (MultiRegion, United States of America)

Does a comment made by a federal court during trial during trial support a government witness's credibility? (MultiRegion, United States of America)