Is the government relieved of its Brady v. Maryland duty to disclose evidence favorable to the accused if the defense could obtain the evidence through due diligence?

QUESTION PRESENTED This petition raises an issue on which courts are divided: is the government relieved of its Brady v. Maryland duty disclose evidence favorable to the accused if the defense could obtain the evidence through due diligence? Or is the government only relieved of its duty when the disclosure would be redundant because the defense already has the evidence?