add contracts to Key#get methods to aid static analysis
add contracts to Key#get methods to aid static analysis

GitOrigin-RevId: 3d42339759704bc8d22dc286b8e7fc8415c62ece

allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community