public BuildParameterBuilder projectionSource(String projectionSource) {
        this.projectionSource = projectionSource == null || projectionSource.isEmpty() ? SOURCE : projectionSource;
        return this;
    }
Sets the name of the projection being built as a source.

<p>This means that the given projection is used to populate
a build artifact (for example, a JAR being built by Gradle).

@param projectionSource Projection name.
@return Returns the builder.
smithy-cli/src/main/java/software/amazon/smithy/cli/BuildParameterBuilder.java