21 pub enum MockError {  enum
32 impl Display for MockError {  implementation
51 impl std::error::Error for MockError {}  implementation
100     pub fn ref_at(&self, index: usize) -> Result<Ref<'a, M, T>, MockError> {  in ref_at()  argument
199     pub fn load(&self, index: u16) -> Result<Descriptor, MockError> {  in load()  argument
206     pub fn store(&self, index: u16, value: Descriptor) -> Result<(), MockError> {  in store()  argument
218     pub fn build_chain(&mut self, len: u16) -> Result<u16, MockError> {  in build_chain()  argument
349     fn update_avail_idx(&mut self, value: u16) -> Result<(), MockError> {  in update_avail_idx()  argument
356     fn alloc_indirect_chain(&mut self, len: u16) -> Result<GuestAddress, MockError> {  in alloc_indirect_chain()  argument
379     pub fn add_chain(&mut self, len: u16) -> Result<(), MockError> {  in add_chain()  argument
386     pub fn add_indirect_chain(&mut self, len: u16) -> Result<(), MockError> {  in add_indirect_chain()  argument
428     ) -> Result<DescriptorChain<&M>, MockError> {  in build_multiple_desc_chains()  argument
445     pub fn build_desc_chain(&self, descs: &[Descriptor]) -> Result<DescriptorChain<&M>, MockError> {  in build_desc_chain()  argument
468     pub fn add_desc_chains(&self, descs: &[Descriptor], offset: u16) -> Result<(), MockError> {  in add_desc_chains()  argument