udunits/src/main/java/ucar/units/StandardPrefixDB.java
private void add(final String name, final String symbol,
                   final double definition) throws PrefixExistsException {
    addName(name, definition);
    addSymbol(symbol, definition);
  }
private void add(final String name, final String symbol,
                   final double definition) throws PrefixExistsException {
    addName(name, definition);
    addSymbol(symbol, definition);
  }
Adds a prefix to the database.

@param name       The name of the prefix.
@param symbol     The symbol for the prefix.
@param definition The numeric value of the prefix.
@throws PrefixExistsException Attempt to redefine an existing prefix.