**Concurrency** and **parallelism** both relate to "different things happening more or less at the same time".

But the details between *concurrency* and *parallelism* are quite different.

To see the difference, imagine the following story about burgers:

### Concurrent Burgers { #concurrent-burgers }

You go with your crush to get fast food, you stand in line while the cashier takes the orders from the people in front of you. 😍

the terms of this License in conveying all material for which you do
not control copyright.  Those thus making or running the covered works
for you must do so exclusively on your behalf, under your direction
and control, on terms that prohibit them from making any copies of
your copyrighted material outside their relationship with you.

  Conveying under any other circumstances is permitted solely under

All the dependencies we have seen are a fixed function or class.

But there could be cases where you want to be able to set parameters on the dependency, without having to declare many different functions or classes.

Let's imagine that we want to have a dependency that checks if the query parameter `q` contains some fixed content.

But we want to be able to parameterize that fixed content.

## A "callable" instance { #a-callable-instance }

    /**
     * Source of samples that can be inserted into the user manual
     *
     */
    public abstract DirectoryProperty getSamples();

    /**
     * Working directory for staging directory for intermediate user manual files
     */
    public abstract DirectoryProperty getStagingRoot();

    public abstract DirectoryProperty getStagedDocumentation();

    /**

 * overriding going on amongst the models being used in this test:
 * each model in the lineage is providing a value that is not present
 * anywhere else in the lineage. We are just making sure that values
 * down in the lineage are bubbling up where they should.
 *
 */
@Deprecated
@SuppressWarnings("checkstyle:UnusedLocalVariable")
class ProjectInheritanceTest extends AbstractProjectInheritanceTestCase {

    //     in all.
    // (3) "Successive". We can consider that we are exchanging a block of size d (a[0..d-1]) with a
    //     block of size n-d (a[d..n-1]), where in general these blocks have different sizes. If we
    //     imagine a line separating the first block from the second, we can proceed by exchanging
    //     the smaller of these blocks with the far end of the other one. That leaves us with a
    //     smaller version of the same problem.

 * overriding going on amongst the models being used in this test:
 * each model in the lineage is providing a value that is not present
 * anywhere else in the lineage. We are just making sure that values
 * down in the lineage are bubbling up where they should.
 *
 */
@Deprecated
class ProjectInheritanceTest extends AbstractProjectInheritanceTestCase {

Let's start with an example **use case** and then see how to solve it with this.

Let's imagine that you have some **machine learning models** that you want to use to handle requests. 🤖

The same models are shared among requests, so, it's not one model per request, or one per user or something similar.

      <name>Maven Central Repository</name>
      <url>scp://repo1.maven.org/home/projects/maven/repository-staging/to-ibiblio/maven2</url>
    </repository>
    <snapshotRepository>
      <id>snapshots</id>
      <name>Maven Central Development Repository</name>
      <url>scp://repo1.maven.org/home/projects/maven/repository-staging/snapshots/maven2</url>
    </snapshotRepository>
    <site>
      <id>website</id>

        "paths": {
            "/invoices/": {
                "post": {
                    "summary": "Create Invoice",