Notwithstanding any provisions of article nine-a, chapter six of the code to the contrary, the commission shall have the power and authority to hold executive sessions for the purpose of establishing policy or an agenda and for the purpose of interrogating any witness or witnesses. If a witness desires to testify or be interrogated in a public or open hearing, such witness shall have the right to demand the same and shall not be heard otherwise. Conversely, if a witness desires to testify or be heard in executive session, he shall notify the commission of his desire and shall assign reasons therefor and the commission may, after consideration of the reasons assigned for such request, grant the same. If such request is refused, such refusal shall not constitute grounds for the refusal to testify. The commission may permit members of the staff of the commission to attend and be present during any executive session of the commission, whether for the taking of evidence or otherwise.