IDiamondStorage

struct DiamondStorage {
  mapping(bytes4 => struct IDiamondStorage.FacetAddressAndPosition) selectorToFacetAndPosition;
  mapping(address => struct IDiamondStorage.FacetFunctionSelectors) facetFunctionSelectors;
  address[] facetAddresses;
  address[47] __gap;
}

struct FacetAddressAndPosition {
  address facetAddress;
  uint96 functionSelectorPosition;
}

struct FacetFunctionSelectors {
  bytes4[] functionSelectors;
  uint256 facetAddressPosition;
}

enum FacetCutAction {
  ADD,
  REPLACE,
  REMOVE,
  NOP
}

struct FacetCut {
  address facetAddress;
  enum IDiamondStorage.FacetCutAction action;
  bytes4[] functionSelectors;
}