public RegisterSpec getLocalAssignment() {
    if (result != null && result.getLocalItem() != null) {
      return result;
    }

    return null;
  }
Gets the spec of a local variable assignment that occurs at this instruction, or null if no
local variable assignment occurs. This may be the result register, or for {@code mark-local}
insns it may be the source.

@return {@code null-ok;} a local-associated register spec or null
@see Insn#getLocalAssignment()
android/android_framework/dex-maker/src/main/java/com/android/dx/ssa/SsaInsn.java