@SuppressWarnings("unchecked")
    public B source(SourceLocation sourceLocation) {
        if (sourceLocation == null) {
            throw new IllegalArgumentException("source must not be null");
        }
        source = sourceLocation;
        return (B) this;
    }
Sets the source location of the shape.

@param sourceLocation Source location to set.
@return Returns the builder.
smithy-model/src/main/java/software/amazon/smithy/model/shapes/AbstractShapeBuilder.java