assertNotNull(projectId, "Project ID should not be null");
        assertEquals(
                "com.example:test-project:jar:1.0.0",
                projectId,
                "Should extract project ID from rawModel when effectiveModel is null");
    }

    /**
     * Test extractProjectId with fileModel fallback when both effectiveModel and rawModel are null.
     */
    @Test

Declare the **header parameters** that you need in a **Pydantic model**, and then declare the parameter as `Header`:

{* ../../docs_src/header_param_models/tutorial001_an_py310.py hl[9:14,18] *}

**FastAPI** will **extract** the data for **each field** from the **headers** in the request and give you the Pydantic model you defined.

## Check the Docs { #check-the-docs }

You can see the required headers in the docs UI at `/docs`:

}

func extractMetadata(ctx context.Context, mimesHeader ...textproto.MIMEHeader) (metadata map[string]string, err error) {
	metadata = make(map[string]string)

	for _, hdr := range mimesHeader {
		// Extract all query values.
		err = extractMetadataFromMime(ctx, hdr, metadata)
		if err != nil {
			return nil, err
		}
	}

	// Set content-type to default value if it is not set.

        with:
          name: maven-distributions
          path: maven-dist

      - name: List downloaded files
        shell: bash
        run: ls -la maven-dist

      - name: Extract Maven distribution
        shell: bash
        run: |
          mkdir -p maven-local
          if [ "${{ runner.os }}" = "Windows" ]; then
            unzip maven-dist/apache-maven-*-bin.zip -d maven-local

   * typically useful for {@code return} statements. That leaves the code with two options: Either
   * add the suppression to the whole method (which turns off checking for a large section of code),
   * or extract a variable, and put the suppression on that. However, a local variable typically
   * doesn't work: Because nullness analyses typically infer the nullness of local variables,

   * typically useful for {@code return} statements. That leaves the code with two options: Either
   * add the suppression to the whole method (which turns off checking for a large section of code),
   * or extract a variable, and put the suppression on that. However, a local variable typically
   * doesn't work: Because nullness analyses typically infer the nullness of local variables,

 * certificate.
 *
 * Use of the chain cleaner is necessary to omit unexpected certificates that aren't relevant to
 * the TLS handshake and to extract the trusted CA certificate for the benefit of certificate
 * pinning.
 */
abstract class CertificateChainCleaner {
  @Throws(SSLPeerUnverifiedException::class)
  abstract fun clean(
    chain: List<Certificate>,

        """
        elt = self.element.find('sts:{}'.format(name), _STS_NS)
        return STSElement(self.root_name, elt) if elt is not None else None

    def get_child_text(self, name, strict=True):
        """Extract text of a child element. If strict, and child element is
        not present, raises InvalidXMLError and otherwise returns
        None.

        """
        if strict:
            try:

            PERFORMANCE_DB_USERNAME, gha/gradle/_all/PERFORMANCE_DB_USERNAME
            PERFORMANCE_DB_PASSWORD_TCAGENT, gha/gradle/_all/PERFORMANCE_DB_PASSWORD
      
      - name: Extract database host from URL
        run: |
          # jdbc:mysql://gradle-bt-performance.xyz.eu-central-1.rds.amazonaws.com:3306 -> gradle-bt-performance.xyz.eu-central-1.rds.amazonaws.com

And you could do this even if the data type in the request is not JSON.

For example, in this application we don't use FastAPI's integrated functionality to extract the JSON Schema from Pydantic models nor the automatic validation for JSON. In fact, we are declaring the request content type as YAML, not JSON: