Bug 75786 [typing] correct indentation fails for indented braces
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/JavaIndenter.java
int unit;
		if (assumeOpeningBrace)
			unit= findReferencePosition(offset, Symbols.TokenLBRACE);
		else
			unit= findReferencePosition(offset, peekChar(offset));
		
		
		if (unit == JavaHeuristicScanner.NOT_FOUND)
			return null;
		
		return getLeadingWhitespace(unit);
		
	}
	
	/**
	 * Computes the indentation at <code>offset</code>.
	 * 
	 * @param offset the offset in the document
	 * @return a String which reflects the correct indentation for the line in
	 *         which offset resides, or <code>null</code> if it cannot be
	 *         determined
	 */
	public StringBuffer computeIndentation(int offset) {
		return computeIndentation(offset, false);
	}
	
	/**
	 * Computes the indentation at <code>offset</code>.
	 * 
	 * @param offset the offset in the document