javagit/src/main/java/edu/nyu/cs/javagit/api/commands/GitBranchOptions.java
public void setOptDLower(boolean optDLower) {
    checkCanSetDeleteOption("-d");
    if (optDLower && optDUpper) {
      throw new IllegalArgumentException(ExceptionMessageMap.getMessage("000120")
          + "  -d cannot be used with -D.");
    } 
    this.optDLower = optDLower;
  }
public void setOptDLower(boolean optDLower) {
    checkCanSetDeleteOption("-d");
    if (optDLower && optDUpper) {
      throw new IllegalArgumentException(ExceptionMessageMap.getMessage("000120")
          + "  -d cannot be used with -D.");
    } 
    this.optDLower = optDLower;
  }
Checks whether the -d option should be set and sets it.

@param optDLower True if the -d option should be used, false otherwise.