# Dependencies { #dependencies }

**FastAPI** has a very powerful but intuitive **<abbr title="also known as components, resources, providers, services, injectables">Dependency Injection</abbr>** system.

It is designed to be very simple to use, and to make it very easy for any developer to integrate other components with **FastAPI**.

## What is "Dependency Injection" { #what-is-dependency-injection }

  for _s in _site_packages_dirs:
    _plugin_dir = _os.path.join(_s, "tensorflow-plugins")
    if _os.path.exists(_plugin_dir):
      _ll.load_library(_plugin_dir)
      # Load Pluggable Device Library
      _ll.load_pluggable_device_library(_plugin_dir)

if _os.getenv("TF_PLUGGABLE_DEVICE_LIBRARY_PATH", ""):
  _ll.load_pluggable_device_library(
      _os.getenv("TF_PLUGGABLE_DEVICE_LIBRARY_PATH")
  )

import org.apache.maven.model.merge.MavenModelMerger;
import org.codehaus.plexus.util.StringUtils;

/**
 * Handles normalization of a model.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@Named
@Singleton
@Deprecated(since = "4.0.0")
public class DefaultModelNormalizer implements ModelNormalizer {

    private DuplicateMerger merger = new DuplicateMerger();

import java.util.function.Consumer;

import org.apache.maven.api.annotations.Nullable;
import org.apache.maven.api.cli.InvokerRequest;
import org.apache.maven.api.cli.mvnenc.EncryptOptions;
import org.apache.maven.api.services.Lookup;
import org.apache.maven.cling.invoker.LookupContext;
import org.apache.maven.cling.invoker.LookupInvoker;
import org.apache.maven.cling.utils.CLIReportingUtils;
import org.jline.reader.LineReaderBuilder;

import java.util.function.Consumer;

import org.apache.maven.api.annotations.Nullable;
import org.apache.maven.api.cli.InvokerRequest;
import org.apache.maven.api.cli.mvnup.UpgradeOptions;
import org.apache.maven.api.services.Lookup;
import org.apache.maven.cling.invoker.LookupContext;
import org.apache.maven.cling.invoker.LookupInvoker;
import org.apache.maven.cling.utils.CLIReportingUtils;
import org.jline.reader.LineReaderBuilder;

 * thrown or a simple string message. In addition, a problem carries a hint about its source, e.g. the settings file
 * that exhibits the problem.
 *
 * @deprecated since 4.0.0, use {@link org.apache.maven.api.services.SettingsBuilder} instead
 */
@Deprecated(since = "4.0.0")
public class DefaultSettingsProblem implements SettingsProblem {

    private final String source;

    private final int lineNumber;

import org.apache.maven.api.ProducedArtifact;
import org.apache.maven.api.Service;
import org.apache.maven.api.annotations.Nonnull;
import org.apache.maven.api.di.SessionScoped;
import org.apache.maven.api.services.ArtifactManager;
import org.apache.maven.impl.DefaultArtifact;
import org.apache.maven.impl.InternalSession;
import org.apache.maven.project.MavenProject;
import org.eclipse.sisu.Typed;

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.api.services;

import org.apache.maven.api.Service;
import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Nonnull;

/**

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.api.services;

import java.util.Collection;
import java.util.List;
import java.util.Objects;

import org.apache.maven.api.ProducedArtifact;
import org.apache.maven.api.RemoteRepository;
import org.apache.maven.api.Session;

 * under the License.
 */
package org.apache.maven.cling.transfer;

import java.io.PrintWriter;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;

import org.apache.maven.api.services.MessageBuilderFactory;
import org.eclipse.aether.transfer.TransferCancelledException;
import org.eclipse.aether.transfer.TransferEvent;
import org.eclipse.aether.transfer.TransferResource;

/**