ph-schematron/src/main/java/com/helger/schematron/pure/binding/xpath/PSXPathVariables.java
@Nonnull
  public EChange remove (@Nullable final String sVarName)
  {
    if (StringHelper.hasText (sVarName))
      if (m_aMap.remove (PSXPathQueryBinding.PARAM_VARIABLE_PREFIX + sVarName) == null)
        return EChange.CHANGED;
    return EChange.UNCHANGED;
  }
@Nonnull
  public EChange remove (@Nullable final String sVarName)
  {
    if (StringHelper.hasText (sVarName))
      if (m_aMap.remove (PSXPathQueryBinding.PARAM_VARIABLE_PREFIX + sVarName) == null)
        return EChange.CHANGED;
    return EChange.UNCHANGED;
  }
Remove the variable with the specified name

@param sVarName
The name of the variable to be removed. May be <code>null</code>.
@return {@link EChange#CHANGED} if the variable was removed successfully.
Never <code>null</code>.