constructor(){
    // When, at *certain nodes* we don't want to inject statements
    // because they're an unnecessary expense. ex: `receive`, this
    // can be toggled on/off in the parser
    this.trackStatements = true;

    // These are set by user option and enable/disable the measurement completely
    this.enabled = {
      statements: true,
      functions: true,
      modifiers: true,
      branches: true,
      lines: true
    }

    this.modifierWhitelist = [];
  }
Registers injections points (e.g source location, type) and their associated data with
a contract / instrumentation target. Run during the `parse` step. This data is
consumed by the Injector as it modifies the source code in instrumentation's final step.