code: public function getContentFieldBoostFactor(ContentType $contentType, FieldDefinition $fieldDefinition)
      {
          $typeIdentifier = $contentType->identifier;
          $fieldIdentifier = $fieldDefinition->identifier;
  
          if (!isset($this->map[self::$keyContentFields][$typeIdentifier])) {
              $typeIdentifier = self::$keyAny;
          }
  
          if (!isset($this->map[self::$keyContentFields][$typeIdentifier][$fieldIdentifier])) {
              $fieldIdentifier = self::$keyAny;
          }
  
          if (isset($this->map[self::$keyContentFields][$typeIdentifier][$fieldIdentifier])) {
              return $this->map[self::$keyContentFields][$typeIdentifier][$fieldIdentifier];
          }
  
          return $this->defaultBoostFactor;
      }
docs: Get boost factor for a Content field by the given $contentType and $fieldDefinition.
  
  @param \eZ\Publish\SPI\Persistence\Content\Type $contentType
  @param \eZ\Publish\SPI\Persistence\Content\Type\FieldDefinition $fieldDefinition
  
  @return float