message: Remove the help function
diff: @@ -30,8 +30,7 @@ use ckb_types::{
  use ckb_vm::{
  snapshot::{resume, Snapshot},
  - DefaultMachineBuilder, Error as VMInternalError, InstructionCycleFunc, SupportMachine,
  - Syscalls,
  + DefaultMachineBuilder, Error as VMInternalError, SupportMachine, Syscalls,
  };
  #[cfg(has_asm)]
  @@ -849,13 +848,6 @@ impl<'a, DL: CellDataProvider + HeaderProvider> TransactionScriptsVerifier<'a, D
  }
  }
  - /// Gets the cost model.
  - ///
  - /// Cost model is used to evaluate consumed cycles.
  - pub fn cost_model(&self) -> &'a InstructionCycleFunc {
  - &instruction_cycles
  - }
  -
  /// Prepares syscalls.
  pub fn generate_syscalls(
  &'a self,
  @@ -905,7 +897,7 @@ impl<'a, DL: CellDataProvider + HeaderProvider> TransactionScriptsVerifier<'a, D
  let script_version = self.select_version(&script_group.script)?;
  let core_machine = script_version.init_core_machine(max_cycles);
  let machine_builder = DefaultMachineBuilder::<CoreMachine>::new(core_machine)
  - .instruction_cycle_func(self.cost_model());
  + .instruction_cycle_func(&instruction_cycles);
  let machine_builder = self
  .generate_syscalls(script_version, script_group)
  .into_iter()
  