App For Port    [Arguments]    ${app}
  # Try to launch one app on either port, continue if it fails on port 1 and launch it on port 2, record if it fails on both.
      ${returned_port}    Set Variable    ${1}
    : FOR    ${port_num}    IN    1    2
        ${returned_port}    Set Variable If    ${port_num} == 2    ${2}
        Check App Launch    ${app}    ${port_num}
    Return From Keyword    ${returned_port}