## Usar la instance como una dependencia

Luego, podríamos usar este `checker` en un `Depends(checker)`, en lugar de `Depends(FixedContentQueryChecker)`, porque la dependencia es la instance, `checker`, no la clase en sí.

Y al resolver la dependencia, **FastAPI** llamará a este `checker` así:

```Python
checker(q="somequery")

	// map header, size 3
	// string "Type"
	o = append(o, 0x83, 0xa4, 0x54, 0x79, 0x70, 0x65)
	o = msgp.AppendString(o, string(z.Type))
	// string "Key"
	o = append(o, 0xa3, 0x4b, 0x65, 0x79)
	o = msgp.AppendString(o, z.Key)
	// string "Context"
	o = append(o, 0xa7, 0x43, 0x6f, 0x6e, 0x74, 0x65, 0x78, 0x74)
	o = msgp.AppendString(o, z.Context)
	return
}

// UnmarshalMsg implements msgp.Unmarshaler

        buf.append("12345ABCDE");
        request.setParameter("userCode", buf.toString());
        assertNotNull(userInfoHelper.getUserCodeFromRequest(request));
        buf.append("12345ABCDE");
        request.setParameter("userCode", buf.toString());
        assertNotNull(userInfoHelper.getUserCodeFromRequest(request));
        buf.append("12345ABCDE");

    @Override
    protected String doBuildColumnString(String dm) {
        StringBuilder sb = new StringBuilder();
        sb.append(dm).append(gidNumber);
        sb.append(dm).append(name);
        if (sb.length() > dm.length()) {
            sb.delete(0, dm.length());
        }
        sb.insert(0, "{").append("}");
        return sb.toString();
    }

# o url      -- The URL for connecting database.
# o schema   -- The schema name.
# o user     -- The database user name.
# o password -- The database password.
# o propertiesMap -- The properties that depends on the database.
# o variousMap    -- The various settings about JDBC task.
#
# *The line that starts with '#' means comment-out.
#
map:{
    ; driver   = org.h2.Driver

            buf.append(loginUrl);
            if (loginReqParams.length() > 0) {
                if (loginUrl.indexOf('?') >= 0) {
                    buf.append('&');
                } else {
                    buf.append('?');
                }
                buf.append(loginReqParams);
                if (!responseParams.isEmpty()) {
                    buf.append('&');

      logger.log(
        buildString {
          append("<-- ${response.code}")
          if (response.message.isNotEmpty()) append(" ${response.message}")
          append(" ${redactUrl(response.request.url)} (${tookMs}ms")
          if (!logHeaders) append(", $bodySize body")
          append(")")
        },
      )

      if (logHeaders) {
        val headers = response.headers

		// string "Totals"
		o = append(o, 0x82, 0xa6, 0x54, 0x6f, 0x74, 0x61, 0x6c, 0x73)
		o = msgp.AppendArrayHeader(o, uint32(60))
		for za0002 := range z[za0001].Totals {
			// map header, size 3
			// string "Total"
			o = append(o, 0x83, 0xa5, 0x54, 0x6f, 0x74, 0x61, 0x6c)
			o = msgp.AppendInt64(o, z[za0001].Totals[za0002].Total)
			// string "Size"
			o = append(o, 0xa4, 0x53, 0x69, 0x7a, 0x65)

  public void testLog2HalfEven() {
    for (BigInteger x : POSITIVE_BIGINTEGER_CANDIDATES) {
      int halfEven = BigIntegerMath.log2(x, HALF_EVEN);
      // Now figure out what rounding mode we should behave like (it depends if FLOOR was
      // odd/even).
      boolean floorWasEven = (BigIntegerMath.log2(x, FLOOR) & 1) == 0;
      assertEquals(BigIntegerMath.log2(x, floorWasEven ? HALF_DOWN : HALF_UP), halfEven);
    }
  }

## Use the instance as a dependency { #use-the-instance-as-a-dependency }

Then, we could use this `checker` in a `Depends(checker)`, instead of `Depends(FixedContentQueryChecker)`, because the dependency is the instance, `checker`, not the class itself.

And when solving the dependency, **FastAPI** will call this `checker` like:

```Python