# `APIRouter` class

Here's the reference information for the `APIRouter` class, with all its parameters, attributes and methods.

You can import the `APIRouter` class directly from `fastapi`:

```python
from fastapi import APIRouter
```

::: fastapi.APIRouter
    options:
        members:
            - websocket
            - include_router
            - get
            - put
            - post
            - delete

Connections
===========

Although you provide only the URL, OkHttp plans its connection to your webserver using three types: URL, Address, and Route.

### [URLs](https://square.github.io/okhttp/5.x/okhttp/okhttp3/-http-url/)

URLs (like `https://github.com/square/okhttp`) are fundamental to HTTP and the Internet. In addition to being a universal, decentralized naming scheme for everything on the web, they also specify how to access web resources.

/**
 * Describes a problem that was encountered during model building. A problem can either be an exception that was thrown
 * or a simple string message. In addition, a problem carries a hint about its source, e.g. the POM file that exhibits
 * the problem.
 *
 */
public interface ModelProblem extends BuilderProblem {

    /**
     * Enumeration of model versions that can be validated.

        return iterator.hasNext();
      }

      @Override
      @ParametricNullness
      public T next() {
        return iterator.next();
      }
    };
  }

  /**
   * Simply returns its argument.
   *
   * @deprecated no need to use this
   * @since 10.0
   */
  @InlineMe(
      replacement = "checkNotNull(iterator)",
      staticImports = "com.google.common.base.Preconditions.checkNotNull")

        return iterator.hasNext();
      }

      @Override
      @ParametricNullness
      public T next() {
        return iterator.next();
      }
    };
  }

  /**
   * Simply returns its argument.
   *
   * @deprecated no need to use this
   * @since 10.0
   */
  @InlineMe(
      replacement = "checkNotNull(iterator)",
      staticImports = "com.google.common.base.Preconditions.checkNotNull")

import java.util.Collection;
import java.util.Set;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * {@link Set} implementation that asserts that a given lock is held whenever one of its methods is
 * called.
 */
@NullUnmarked
class LockHeldAssertingSet<E> extends ForwardingSet<E> implements Serializable {
  final Set<E> delegate;
  final Object mutex;

            return (Class<T>) Class.forName(className, true, loader);
        } catch (final Throwable ignore) {
            return null;
        }
    }

    /**
     * If the class is a primitive type, returns its wrapper class.
     *
     * @param className
     *            The class name. Must not be {@literal null} or empty.
     * @return {@link Class}
     * @throws EmptyArgumentException

# About { #about }

// constant) is one of the TBL-like instructions and one of its
// inputs does not fit into prog.Reg, so require special handling.
func IsARM64TBL(op obj.As) bool {
	switch op {
	case arm64.AVTBL, arm64.AVTBX, arm64.AVMOVQ:
		return true
	}
	return false
}

// IsARM64CASP reports whether the op (as defined by an arm64.A*
// constant) is one of the CASP-like instructions, and its 2nd

@NullMarked
public final class SerializableTester {
  private SerializableTester() {}

  /**
   * Serializes and deserializes the specified object.
   *
   * <p><b>GWT warning:</b> Under GWT, this method simply returns its input, as proper GWT
   * serialization tests require more setup. This no-op behavior allows test authors to intersperse
   * {@code SerializableTester} calls with other, GWT-compatible tests.
   *