* @param algorithms  The checksum algorithms to use, must not be {@code null}.
     * @return The calculated checksums, indexed by algorithms, never {@code null}.
     * @throws NullPointerException if passed in any parameter is {@code null}.
     */
    @Nonnull
    Map<ChecksumAlgorithm, String> calculate(@Nonnull byte[] data, @Nonnull Collection<ChecksumAlgorithm> algorithms);

    /**
     * Calculates checksums for specified data.

        </executions>
      </plugin>
      <plugin>
        <groupId>com.github.siom79.japicmp</groupId>
        <artifactId>japicmp-maven-plugin</artifactId>
        <configuration>
          <parameter>
            <includes>
              <include>org.apache.maven.toolchain.model</include>
            </includes>
            <excludes>

# Header Parameters { #header-parameters }

You can define Header parameters the same way you define `Query`, `Path` and `Cookie` parameters.

## Import `Header` { #import-header }

First import `Header`:

{* ../../docs_src/header_params/tutorial001_an_py310.py hl[3] *}

## Declare `Header` parameters { #declare-header-parameters }

Then declare the header parameters using the same structure as with `Path`, `Query` and `Cookie`.

## OpenAPI operationId { #openapi-operationid }

/// warning

If you are not an "expert" in OpenAPI, you probably don't need this.

///

You can set the OpenAPI `operationId` to be used in your *path operation* with the parameter `operation_id`.

You would have to make sure that it is unique for each operation.

{* ../../docs_src/path_operation_advanced_configuration/tutorial001_py310.py hl[6] *}

```python
from typing import Optional


def say_hi(name: Optional[str]):
    print(f"Hey {name}!")
```

The parameter `name` is defined as `Optional[str]`, but it is **not optional**, you cannot call the function without the parameter:

```Python
say_hi()  # Oh, no, this throws an error! 😱
```

The `name` parameter is **still required** (not *optional*) because it doesn't have a default value. Still, `name` accepts `None` as the value:

     *             installation has failed
     * @throws IllegalArgumentException if {@code request} is {@code null} or parameter
     *             {@code localRepository} is {@code null} or {@code localRepository} is not a directory
     *             or parameter {@code mavenArtifacts} is {@code null} or
     *             {@code mavenArtifacts.isEmpty()} is {@code true}.
     */

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

/**
 * An implementation of {@link GraphConnections} for undirected graphs.
 *
 * @author James Sexton
 * @param <N> Node parameter type
 * @param <V> Value parameter type
 */
final class UndirectedGraphConnections<N, V> implements GraphConnections<N, V> {
  private final Map<N, V> adjacentNodeValues;

            }
        });
    }

    /**
     * Retrieves a parameter value from the data store parameters map.
     *
     * @param paramMap the parameter map to search
     * @param key the parameter key to look up
     * @param defaultValue the default value to return if key is not found
     * @return the parameter value as a string, or the default value if not found
     */

                if (oldNullability && !newNullability) {
                    errors << "Parameter $idx from null accepting to non-null accepting breaking change".toString()
                } else if (!oldNullability && newNullability) {
                    warnings << "Parameter $idx nullability changed from non-nullable to nullable".toString()
                }
            }
        }

    //                                     Parameter Logging
    //                                     -----------------
    // logging filter cannot show the parameters when multi-part so logging here
    protected void showFieldLoggingTitle() {
        if (logger.isDebugEnabled()) {
            logger.debug("[Multipart Request Parameter]");
        }
    }