// may be set to the cause for the failure.
// The check parameter may be nil if convertibleTo is invoked through an
// exported API call, i.e., when all methods have been type-checked.
func (x *operand) convertibleTo(check *Checker, T Type, cause *string) bool {
	// "x is assignable to T"
	if ok, _ := x.assignableTo(check, T, cause); ok {
		return true
	}

	origT := T
	V := Unalias(x.typ)
	T = Unalias(T)

int OpView::NumOutputs() const { return output_args_.size(); }

ArgView OpView::OnlyInput() const {
  CHECK_EQ(input_args_.size(), 1);  // Crash OK
  return input_args_.front();
}

ArgView OpView::OnlyOutput() const {
  CHECK_EQ(output_args_.size(), 1);  // Crash OK
  return output_args_.front();
}

string OpView::FunctionName() const { return op_.name(); }

   * RuntimeException runtime exceptions} thrown by the executor.
   */
  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
  private static void executeListener(Runnable runnable, Executor executor) {
    try {
      executor.execute(runnable);
    } catch (Exception e) { // sneaky checked exception
      // Log it and keep going -- bad runnable and/or executor. Don't punish the other runnables if

   * RuntimeException runtime exceptions} thrown by the executor.
   */
  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
  private static void executeListener(Runnable runnable, Executor executor) {
    try {
      executor.execute(runnable);
    } catch (Exception e) { // sneaky checked exception
      // Log it and keep going -- bad runnable and/or executor. Don't punish the other runnables if

   */
  protected void verify(List<E> elements) {}

  /** Executes the test. */
  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
  public final void test() {
    try {
      recurse(0);
    } catch (Exception e) { // sneaky checked exception
      throw new RuntimeException(Arrays.toString(stimuli), e);
    }
  }

  private void recurse(int level) {

	return validators
}

// addIPv6Checks adds IPv6 related checks
func addIPv6Checks(checks []Checker) []Checker {
	checks = append(checks,
		FileContentCheck{Path: ipv6DefaultForwarding, Content: []byte{'1'}},
	)
	return checks
}

// addIPv4Checks adds IPv4 related checks
func addIPv4Checks(checks []Checker) []Checker {
	checks = append(checks,
		FileContentCheck{Path: ipv4Forward, Content: []byte{'1'}})
	return checks

      checkElementsNotNull(elements, n);
      getReadyToExpandTo(size + n);
      /*
       * The following call is not statically checked, since arraycopy accepts plain Object for its
       * parameters. If it were statically checked, the checker would still be OK with it, since
       * we're copying into a `contents` array whose type allows it to contain nulls. Still, it's

import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Set;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An immutable sorted set with one or more elements. TODO(jlevy): Consider separate class for a
 * single-element sorted set.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 */

```Python hl_lines="16"
{!../../../docs_src/dependencies/tutorial011.py!}
```

这样就可以**参数化**依赖项，它包含 `checker.fixed_content` 的属性 - `"bar"`。

## 把实例作为依赖项

然后，不要再在 `Depends(checker)` 中使用 `Depends(FixedContentQueryChecker)`， 而是要使用 `checker`，因为依赖项是类实例 - `checker`，不是类。

处理依赖项时，**FastAPI** 以如下方式调用 `checker`：

```Python
checker(q="somequery")
```

……并用*路径操作函数*的参数 `fixed_content_included` 返回依赖项的值：

```Python hl_lines="20"

	finalSwitchCase
	inTypeSwitch
)

func (check *Checker) simpleStmt(s ast.Stmt) {
	if s != nil {
		check.stmt(0, s)
	}
}

func trimTrailingEmptyStmts(list []ast.Stmt) []ast.Stmt {
	for i := len(list); i > 0; i-- {
		if _, ok := list[i-1].(*ast.EmptyStmt); !ok {
			return list[:i]
		}
	}
	return nil
}

func (check *Checker) stmtList(ctxt stmtContext, list []ast.Stmt) {