value-processor/src/org/immutables/value/processor/meta/AttributeBuilderDescriptor.java
public String getQualifiedValueToBuilderMethod() {
    switch (getValueToBuilderTarget()) {

      case VALUE_INSTANCE:
        return getValueToBuilderMethod();
      case VALUE_TYPE:
        return String.format("%s.%s", getQualifiedValueTypeName(), getValueToBuilderMethod());
      case BUILDER_INSTANCE:
        return String
            .format("%s().%s", getQualifiedBuilderConstructorMethod(), getValueToBuilderMethod());
      case BUILDER_TYPE:
        return String.format("%s.%s", getQualifiedBuilderTypeName(), getValueToBuilderMethod());
      case BUILDER_CONSTRUCTOR:
        return getQualifiedBuilderConstructorMethod();
      default:
        throw new UnsupportedOperationException(
            String.format("Could not handle %s", getValueToBuilderTarget()));
    }
  }
public String getQualifiedValueToBuilderMethod() {
    switch (getValueToBuilderTarget()) {

      case VALUE_INSTANCE:
        return getValueToBuilderMethod();
      case VALUE_TYPE:
        return String.format("%s.%s", getQualifiedValueTypeName(), getValueToBuilderMethod());
      case BUILDER_INSTANCE:
        return String
            .format("%s().%s", getQualifiedBuilderConstructorMethod(), getValueToBuilderMethod());
      case BUILDER_TYPE:
        return String.format("%s.%s", getQualifiedBuilderTypeName(), getValueToBuilderMethod());
      case BUILDER_CONSTRUCTOR:
        return getQualifiedBuilderConstructorMethod();
      default:
        throw new UnsupportedOperationException(
            String.format("Could not handle %s", getValueToBuilderTarget()));
    }
  }
Uses {@link #getValueToBuilderTarget()} to determine appropriate format for
creating a new builder from a value object.

The template needs to still query {@link #isCopyMethodOnValueInstance()} to determine
whether to use {@code [expression].[n.getQualifiedValueToBuilderMethod]()} vs
{@code [n.getQualifiedValueToBuilderMethod]([expression])}

@return method to use for converting a value to a builder.