public boolean addWS() {
		WhiteSpace last = lastWhiteSpace();
		if (last != null) {
			return false;
		}
		return addSymbol(WHITE_SPACE);
	}
Add optional whitespace, if not already preceded by whitespace

@return true if whitespace was added
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/assembler/sleigh/grammars/AssemblySentential.java